I tried to sync from Linux Mint (64-bit Intel/AMD) Syncthing v2.1.0 device to Linux Nobara (64-bit Intel/AMD) Syncthing v 1.30.0 and noticed lots of protocol errors with request size 0 too small in the logs. What does it mean?
For example: 2026-05-25 11:01:30 INF Lost device connection (kind=primary device=E723UTH connection=192.168.178.21:22000-192.168.178.20:22000/tcp-client/TLS1.3-TLS_CHACHA20_POLY1305_SHA256/LAN-P10-65IODMAGA[REDACTED³] error="protocol error on request for \"FAU/1. Semester/WS2019_20.txt\" in zgeph-pvpqa: request size 0 too small" remaining=0 log.pkg=model)
I also had connection issues during the sync. Might be related. After the sync was done, the connection seemed more stable.
The protocol errors mostly showed for empty.txt files, but some other files were affected too. The few files I checked, held no content, but I cannot rule out that some contained something.
2026-05-25 11:01:14 INF Established secure connection (device=E723UTH connection.local=192.168.178.21:22000 connection.remote=192.168.178.20:22000 connection.type=tcp-client connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=65IODMAGA[REDACTED³] log.pkg=connections)
2026-05-25 11:01:14 INF Additional device connection (device=E723UTH address=192.168.178.20:22000 count=1 log.pkg=model)
2026-05-25 11:01:24 INF Lost device connection (kind=primary device=E723UTH connection=192.168.178.21:22000-192.168.178.20:22000/quic-server/TLS1.3-TLS_CHACHA20_POLY1305_SHA256/LAN-P20-65IODLNP[REDACTED4] error="reading length: Application error 0x0 (remote): closing" remaining=1 log.pkg=model)
2026-05-25 11:01:29 INF Established secure connection (device=E723UTH connection.local=192.168.178.21:22000 connection.remote=192.168.178.20:22000 connection.type=quic-server connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=20 connection.id=65IODO[REDACTED²] log.pkg=connections)
2026-05-25 11:01:29 INF New device connection (device=E723UTH address=192.168.178.20:22000 remote.name=Thilo-X570-Linux remote.client=syncthing remote.version=v1.30.0 log.pkg=model)
2026-05-25 11:01:30 INF Lost device connection (kind=primary device=E723UTH connection=192.168.178.21:22000-192.168.178.20:22000/tcp-client/TLS1.3-TLS_CHACHA20_POLY1305_SHA256/LAN-P10-65IODMAGA[REDACTED³] error="protocol error on request for \"FAU/1. Semester/WS2019_20.txt\" in zgeph-pvpqa: request size 0 too small" remaining=0 log.pkg=model)
2026-05-25 11:01:30 INF Connection closed (device=E723UTH connection=192.168.178.21:22000-192.168.178.20:22000/tcp-client/TLS1.3-TLS_CHACHA20_POLY1305_SHA256/LAN-P10-65IODMAGA[REDACTED³] error="protocol error on request for \"FAU/1. Semester/WS2019_20.txt\" in zgeph-pvpqa: request size 0 too small" log.pkg=model)
2026-05-25 11:01:34 INF Established secure connection (device=E723UTH connection.local=192.168.178.21:22000 connection.remote=192.168.178.20:22000 connection.type=tcp-client connection.lan=true connection.crypto=TLS1.3-TLS_CHACHA20_POLY1305_SHA256 connection.prio=10 connection.id=65IODOL[REDACTED] log.pkg=connections)
2026-05-25 11:01:34 INF Additional device connection (device=E723UTH address=192.168.178.20:22000 count=1 log.pkg=model)
2026-05-25 11:01:44 INF Lost device connection (kind=primary device=E723UTH connection=192.168.178.21:22000-192.168.178.20:22000/quic-server/TLS1.3-TLS_CHACHA20_POLY1305_SHA256/LAN-P20-65IODO[REDACTED²] error="replacing connection" remaining=1 log.pkg=model)
