Github desktop sync not working

Describes the cause and action for error messages.

Error Message(English)：
desktop sync not working

Resolution

Sync button on Github Desktop (mac) not working
https://stackoverflow.com/questions/49682802/sync-button-on-github-desktop-mac-not-working

my github desktop doesn't work
https://stackoverflow.com/questions/41768241/my-github-desktop-doesnt-work

Github desktop sync spins indefinitely
https://stackoverflow.com/questions/34005958/github-desktop-sync-spins-indefinitely

Github commit not working on desktop app
https://stackoverflow.com/questions/32199449/github-commit-not-working-on-desktop-app

GitHub Desktop is not pushing/updating/syncing - GitHub Community ...
https://github.community/t5/How-to-use-Git-and-GitHub/GitHub-Desktop-is-not-pushing-updating-syncing・・・

Unable to sync repositories using GitHub Desktop: fatal error ...
https://github.com/desktop/desktop/issues/3156

What happened to the Sync button of the previous client? - GitHub
https://github.com/desktop/desktop/issues/1802

history UI out of sync with repository after pulling with merge - GitHub
https://github.com/desktop/desktop/issues/2737

Syncing your branch - GitHub Help
https://help.github.com/en/desktop/contributing-to-projects/syncing-your-branch