Today, on one device after rebooting the OS and starting Syncthing in the process, I’m experiencing the Web GUI being completely stalled:
It has been in this state for ~40 minutes or so, and the device in question appears disconnected on other devices. The hardware is decent, and normally everything works just fine.
I’m uploading a full goroutine dump below. I also wanted to take CPU and heap profiles, but I cannot, as the browser just keeps trying to load the /rest/debug/heapprof URLs (as by https://docs.syncthing.net/users/profiling.html) with no end to it.
- goroutine.txt (378.1 KB)
The log is also basically flooded with these:
[3KHRD] 2025/05/24 18:57:35 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 18:59:51 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:1139: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:00:06 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:1139: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:00:20 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::d5c2:2f0d:e1d2:13ce%Wi-Fi 4]:22000->[fe80::2c0a:f886:fe67:b899%Wi-Fi 4]:60859: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:01:06 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:02:26 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:02:37 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:1139: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:03:51 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::d5c2:2f0d:e1d2:13ce%Wi-Fi 4]:22000->[fe80::2c0a:f886:fe67:b899%Wi-Fi 4]:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:04:57 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:22000: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:06:22 INFO: Listen (BEP/tcp): TLS handshake: read tcp [fe80::d5c2:2f0d:e1d2:13ce%Wi-Fi 4]:22000->[fe80::2c0a:f886:fe67:b899%Wi-Fi 4]:60882: wsarecv: An existing connection was forcibly closed by the remote host.
[3KHRD] 2025/05/24 19:08:53 INFO: Listen (BEP/tcp): TLS handshake: read tcp 192.168.50.253:22000->192.168.50.1:22000: wsarecv: An existing connection was forcibly closed by the remote host.
This is Windows 11 x64, and Syncthing has been built from https://github.com/tomasz1986/syncthing/tree/tomasz86/releases/tomasz86-v2.0.0-rc.16.
I’d be very grateful if you could have a look at the goroutine dump and let me know if there is anything obvious in there 
.
Edit:
I had to bring the device back to life, so I just killed the Syncthing process and restarted it. After doing so, it launched and began to sync as usual, so I’m really not sure what had happened before…