Syncthing unresponsive with "wsarecv: An existing connection was forcibly closed by the remote host"

tomasz86 · January 7, 2025, 5:25pm

Today, on one of my devices, Syncthing got completely unresponsive with the log flooded with the following messages:

[UDPWE] 2025/01/07 15:57:39 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57265: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:02:06 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57285: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:06:08 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57327: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:06:54 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:07:08 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57332: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:08:09 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:10:09 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57360: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:10:40 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57364: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:11:57 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:13:12 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57388: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:14:49 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:17:00 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:17:47 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57417: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:19:32 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55035: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:21:20 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57434: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:27:35 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55063: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:29:06 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55069: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:30:07 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55072: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:30:50 INFO: Listen (BEP/tcp): TLS handshake: read tcp 10.0.0.106:22000->10.0.0.102:55074: i/o timeout
[UDPWE] 2025/01/07 16:32:39 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55086: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:35:10 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55095: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:37:09 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55102: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:37:42 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55105: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:40:46 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55119: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:43:18 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55129: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:45:49 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55138: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:51:52 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55160: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:53:53 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55168: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:56:24 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55177: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:56:55 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55179: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 16:57:55 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:04:27 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55212: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:08:30 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:12:30 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55240: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:14:01 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55246: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:18:02 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57840: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:19:04 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55264: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:20:05 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55269: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:20:34 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57855: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:25:38 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57905: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:26:04 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57907: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:27:08 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55295: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:28:08 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55298: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:28:09 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57922: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:29:39 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55304: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:30:39 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55308: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:30:40 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57942: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:31:07 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:57943: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:31:26 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:35:43 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55331: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:38:14 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55340: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:39:45 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55346: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:40:46 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55351: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:43:46 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55361: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:45:17 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55367: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:46:18 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55377: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:49:20 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:51:21 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55395: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:52:21 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55399: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:54:21 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55405: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:56:18 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58386: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:56:39 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58391: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:56:53 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55415: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 17:58:10 INFO: Listen (BEP/relay): joining session: incorrect response code 2: already connected
[UDPWE] 2025/01/07 17:59:24 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55424: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:01:56 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55437: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:03:53 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58455: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:04:14 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58457: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:04:55 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55451: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:06:24 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58467: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:06:45 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58472: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:07:27 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55461: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:08:55 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58488: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:11:47 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::80f0:6025:c2ca:dc55%Wi-Fi]:58503: wsarecv: An existing connection was forcibly closed by the remote host.
[UDPWE] 2025/01/07 18:12:30 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::40d8:6a9a:f4a3:903e%Wi-Fi]:22000->[fe80::ebcd:cd9d:2db4:68eb%Wi-Fi]:55480: wsarecv: An existing connection was forcibly closed by the remote host.

Neither synchronisation itself nor the GUI works - everything is stuck in this unresponsive state.

Unfortunately, I haven’t got profiling enabled to provide any more detailed information . This is essentially Syncthing v1.29.0 (but compiled with Go v1.22) running under Windows 11.

I’m now going to kill the process and restart it manually, but has anyone got any idea what the issue may be about? This the very first time I’m seeing this problem. I can also add that Syncthing on the device was upgraded to v1.29.0 yesterday.

ekim501 · January 8, 2025, 5:11am

I’m having the same issue on all my systems v1.29.0 Windows 10 / 11. I have around 20 desktops and I have to keep restarting syncthing on all of them to get it running again. Downgrading to v1.28.1 fixed the issue.

tomasz86 · January 8, 2025, 9:40am

Good to know I’m not alone with the issue…

Here, the problem fortunately affected only the single device once, and it hasn’t repeated itself since then yet.

Edit:

I’m now seeing exactly the same problem on yet another device. The log is filled with

[3KHRD] 2025/01/08 15:27:58 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::8e58:2ba0:d711:a80f%Wi-Fi 3]:22000->[fe80::2c0a:f886:fe67:b899%Wi-Fi 3]:22000: wsarecv: An existing connection was forcibly closed by the remote host.

and Syncthing has stopped responding completely. I’m now going to make sure that STPROFILER is enabled, and then I will try to get a goroutine stack dump once Syncthing gets stuck again.

Moisie · January 9, 2025, 12:46pm

Hi:

FWIW I’m seeing the same behaviour (though not with the TLS handshake messages) with two Synology NAS units having auto-dated from 1.28.1 → 1.29.0.

Reverting to 1.28.1 has restored correct behaviour for me.

tomasz86 · January 9, 2025, 4:11pm

The device is stuck in the same unresponsive state again. This time, profiling was enabled and I’ve managed to grab a full goroutine stack dump.

goroutine.txt (547.7 KB)
goroutine.txt (632.9 KB)

I’d be very thankful if anyone knowledgeable enough could check and see if there’s anything obvious in there.

Edit: Added yet another goroutime dump from the second device experiencing the same problem. Just for the record, Syncthing has been built from https://github.com/tomasz1986/syncthing/tree/tomasz86/releases/tomasz86-v1.29.0.

calmh · January 9, 2025, 5:59pm

Thank you for that @tomasz86, I see the deadlock and will fix it.

calmh · January 9, 2025, 6:52pm

I’m releasing a 1.29.1 with a fix for this in a couple of hours, hoping to get some sort of clarity on the login calamity as well before then… but if not, I’ll release anyway for the time being.

tomasz86 · January 9, 2025, 7:11pm

Great !

I’ve cherry-picked the commit and I’m going to test it in my build very soon.