Syncthing not opening GUI on Windows

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1

I was using Syncthing via SyncTrayzor on Windows 11, until all of a sudden, the program would not open the GUI. I deleted all traces of Syncthing from my drive, then downloaded and ran the latest 1.20.4 version for 64 bit Windows. The terminal output looks okay, however trying to connect to the GUI (127.0.0.1:8384) times out on every browser I try.

Here’s the output:

[monitor] 2022/08/14 16:32:40 INFO: Log output saved to file "C:\Users\mmael\AppData\Local\Syncthing\syncthing.log"
[start] 2022/08/14 16:32:40 INFO: syncthing v1.20.4 "Fermium Flea" (go1.18.4 windows-amd64) teamcity@build.syncthing.net 2022-08-02 08:10:29 UTC
[NU5FI] 2022/08/14 16:32:41 INFO: My ID: NU5FIFA-YLTGM5T-SM5PIAM-CFNKKGA-QAKM3VQ-EG6O4H7-WYLFUKS-QM25KQH
[NU5FI] 2022/08/14 16:32:42 INFO: Single thread SHA256 performance is 357 MB/s using crypto/sha256 (354 MB/s using minio/sha256-simd).
[NU5FI] 2022/08/14 16:32:42 INFO: Hashing performance is 301.44 MB/s
[NU5FI] 2022/08/14 16:32:42 INFO: Overall send rate is unlimited, receive rate is unlimited
[NU5FI] 2022/08/14 16:32:42 INFO: Relay listener (dynamic+https://relays.syncthing.net/endpoint) starting
[NU5FI] 2022/08/14 16:32:42 INFO: Using discovery mechanism: global discovery server https://discovery.syncthing.net/v2/?noannounce&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW
[NU5FI] 2022/08/14 16:32:42 INFO: Using discovery mechanism: global discovery server https://discovery-v4.syncthing.net/v2/?nolookup&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW
[NU5FI] 2022/08/14 16:32:42 INFO: Using discovery mechanism: global discovery server https://discovery-v6.syncthing.net/v2/?nolookup&id=LYXKCHX-VI3NYZR-ALCJBHF-WMZYSPK-QG6QJA3-MPFYMSO-U56GTUK-NA2MIAW
[NU5FI] 2022/08/14 16:32:42 INFO: Using discovery mechanism: IPv4 local broadcast discovery on port 21027
[NU5FI] 2022/08/14 16:32:42 INFO: Using discovery mechanism: IPv6 local multicast discovery on address [ff12::8384]:21027
[NU5FI] 2022/08/14 16:32:42 INFO: Ready to synchronize "Default Folder" (default) (sendreceive)
[NU5FI] 2022/08/14 16:32:42 INFO: Completed initial scan of sendreceive folder "Default Folder" (default)
[NU5FI] 2022/08/14 16:32:42 INFO: GUI and API listening on 127.0.0.1:8384
[NU5FI] 2022/08/14 16:32:42 INFO: Access the GUI via the following URL: http://127.0.0.1:8384/
[NU5FI] 2022/08/14 16:32:42 INFO: My name is "mmaT580-windows"
[NU5FI] 2022/08/14 16:32:42 INFO: QUIC listener ([::]:22000) starting
[NU5FI] 2022/08/14 16:32:42 INFO: TCP listener ([::]:22000) starting
[NU5FI] 2022/08/14 16:32:52 INFO: Detected 0 NAT services
[NU5FI] 2022/08/14 16:32:54 INFO: quic://0.0.0.0:22000 detected NAT type: Symmetric NAT
[NU5FI] 2022/08/14 16:34:01 INFO: Joined relay relay://184.105.151.166:22067
[NU5FI] 2022/08/14 16:37:30 INFO: Joined relay relay://23.172.144.29:443
[NU5FI] 2022/08/14 16:38:13 INFO: quic://0.0.0.0:22000 detected NAT type: Port restricted NAT
[NU5FI] 2022/08/14 16:38:13 INFO: quic://0.0.0.0:22000 resolved external address quic://24.244.23.214:2976 (via stun.syncthing.net:3478)

I am not aware of any changes I’ve made that could’ve caused this, but just in case, I allowed syncthing.exe through Windows Firewall, disabled VPN, disabled Portmaster, and disabled Lenovo’s WiFi security. I’ve rebooted and the problem remains. Please help!

  • Windows 11 version 21H2
  • Syncthing 1.20.4 Windows x86-64
2

Everything looks fine in the command line output, but seeing

I can only say that you’ve a lot of stuff going on there. Are you absolutely sure you need all of that software (especially the last one)? When it comes to Windows and those kind of security solutions, it’s often the case that disabling them isn’t enough. You may want to try uninstalling everything and check what the situation is then first.

3

For the record, the Lenovo WiFi security was part of Vantage, and it was disabled before I started having Syncthing issues. Regardless, it seems like uninstalling Portmaster did the trick, although I recall it working before with it installed. Thanks for your help.

4

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