This is currently being investigated by our teams.
In the meantime, please try the following workaround:
• Open the Run command by pressing the R key and Windowskey at the same time.
• Type in %AppData% and confirm by pressing Enter or by clicking OK.
• Navigate to the following directory: C:\Users\Username\AppData\Local.
• Delete the Ubisoft Game Launcher folder.
You should now be able to start Ubisoft Connect again.
Should you have any other questions, do not hesitate to contact us!