JetBrains Daemon isn't running: exit code 101 (DE_ELEVATION_FAILURE) on Windows

Problem

On Windows, the Toolbox App reports JetBrains Daemon isn't running and retries about once a minute. jetbrains:// links, joining an organization, and SSH connections stop working.

The launcher log under %LocalAppData%\JetBrains\Daemon\logs shows this on every attempt:

ERROR elevation - De-elevation failed: CreateProcessWithTokenW() failed, error=740
ERROR elevation - Failed to start de-elevated daemon process

Cause

The Toolbox App runs elevated, and jetbrainsd process inherits that. jetbrainsd is prohibited from running elevated by design, so the launcher tries to respawn it under a de-elevated token, and that spawn fails.

RUNASADMIN compatibility layer set on the Toolbox App executable may be a root cause. The Toolbox App log under %LocalAppData%\JetBrains\Toolbox\logs shows it at startup:

INFO  main  BootstrapLogger  __COMPAT_LAYER = RunAsAdmin

Resolution

Quit the Toolbox App, then end any remaining jetbrains-toolbox.exe process in Task Manager. Clear the administrator flag in all three places below:

1. The shortcut. Right-click the Toolbox App shortcut, select Properties | Shortcut | Advanced, and clear Run as administrator.
2. The executable. Open Properties | Compatibility on %LocalAppData%\JetBrains\Toolbox\bin\jetbrains-toolbox.exe itself, and clear Run this program as an administrator.
3. The registry. In the Registry Editor, delete any value naming jetbrains-toolbox.exe or jetbrainsd.exe under either key:

HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers

4. Start the Toolbox App as usual.