Unable to switch to New Teams (work and school) (FIXED!)

Ahead of the April 1st switchover, I have a user with a rather peculiar issue: he is facing this banner when trying to change to the New Microsoft Teams (work and school): "Something went wrong, and we couldn't open the new teams. Please try again."

Steps tried to resolve: 

• Cleared the Classic Teams cache

• Cleared the New Teams cache

• Added a Reg_Dword to registry (BlockNonAdminUserInstall) Set value to 0
  Registry path: Software\Policies\Microsoft\Windows\Appx

The above steps did not work. 

Solution: 

Uninstall Teams Classic

Online Repair of Microsoft 365 suite (which now includes MS Teams) resolved the issue entirely.