Solution:

1. To solve this issue, follow the below steps:
2. Click on the "Start" button in the Windows Toolbar
3. Search for "Privia User Options"
4. Open the Applications
5. Click the buttons "Clear Logon Settings" and "Clear Passwords" (This action forces the .NET framework to flush the cache of stored passwords.)
6. Open Privia Profiler back up and try to register again

Notes:

If you still cannot register with the Privia Profiler, get in contact with you Privia Administrator to further troubleshoot the issue