You can remove this error by following the steps given below.
- Uninstall the Ubisoft Games Launcher, Go to the start menu then search for Ubisoft games launcher then right-click and uninstall it.
- Then go to C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher and delete any files that are left.
- Then reinstall the Ubisoft game launcher from here.
- Complete the online authentication in the app and you are good to go.
Do not disable the launcher or uninstall the launcher as it is required to play games by ubisoft.
Always keep your launcher updated to the latest version. If it is a problem with only a single game then you can contact Ubisoft support.