Beta Features Enabled: i deleted my Roblox appdata folder and the installation i had, tried on a few different accounts and it still happens.
Expected behavior
Open the studio place page or starter page.
Current Solution
Open regedit
Go to Computer\HKEY_CURRENT_USER\SOFTWARE\Roblox\RobloxStudio
Rename it to something else
Start studio and you should be able to log into the account