Windows 10 February 11, 2020 updates cause Syncthing startup problems

After three of my Windows 10 x64 computers updated with

  • KB4532693 (OS Builds 18362.657 and 18363.657)
  • KB4534132 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1903 and Windows Server 1903 RTM and Windows 10 , version 1909 and Windows Server, version 1909
  • KB4537759 Security Update for Adobe Flash Player: February 11, 2020

Syncthing couldn’t start with the message “Unable to start Syncthing: RestEase Error.”:


I had syncthing v1.1.1 "Erbium Earthworm" (go1.12.1 windows-amd64) 2019-03-25 11:43:21 UTC and putting the newest version of syncthing.exe into the SyncTrayzor folder made it work again.

Just reporting … :grinning:

I suggest you start syncthing without synctrayzor and see what the actual cause is.

This is not related to Windows Update, but a known issue with Syncthing and SyncTrayzor:

(Also this: `rest/db/status` returns 404 on startup)

1 Like

A test maybe is good. Starting Syncthing without SyncTrayzor offers a result. The same updates I also made on Windows 10 without any problems.

Generally I use Syncthing without SyncTrayzor with the Task Scheduler:

Start the Task Scheduler (taskschd.msc)

Create a New Task (“Action” menu -> “Create Task…”)

General Tab:

        Name the task (for example ‘Syncthing’)

        Check “Run whether user is logged on or not”

Triggers Tab:

        Click “New…”

        Set “Begin the task” to “At Startup”

        (optional) choose a delay

        Make sure Enabled is checked

        Click “OK”

Actions Tab:

        Click “New…”

        [Action] should be set as “Start a program”

        Enter the path to syncthing.exe in “Program/Script”

        (optional) Enter “-no-console -no-browser” for “Add arguments (optional)”

        Click “OK”

Settings Tab:

        (recommended) Keep the checkbox on “Allow task to be run on demand”

        Clear checkbox from “Stop task if it runs longer than:”

        (recommended) Keep “Do not start a new instance” for “If the task is already running, then the following rule applies”

Click OK

Enter password for the user.