After a fresh installation of Windows 11 I am unable to see some of my VB projects in the projects window. These projects were locked for viewing and had passwords set. I know the passwords.
Before the refresh, I could see them listed and was able to operate normally with them. Now, they just don't appear in the VBE Project Explorer. However, they do appear in the PowerPoint Add-in in the Developer tab.
Assuming that you mean you can see your add-ins listed in the VBA IDE:
Quit PPT if it's running. Start REGEDIT Locate:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\PowerPoint\Options
Under Options, add a new DWORD value named DebugAddins
Set its value to 1
Close REGEDIT, start PPT.