After I rebuilt my SharePoint Server I moved across one last database. After a restart SharePoint reported that the database was in compatibility mode.

I opened up an elevated SharePoint PowerShell and ran the following command:

  • PSConfig.exe -cmd upgrade -inplace b2b -force

PSConfig went through the steps and got stuck on Step 3. This has to be a permission problem. Remembering that on my old server I made changes to the registry permissions.

I ran regedit and navigated to the following key:

  • HKEY_LOCAL_MACHINESoftwareMicrosoftShared ToolsWeb Server Extensions15.0Secure

If you right click on the secure key and click permissions you will see the WSS_ADMIN_WPG and WSS_WPG users. I granted both full access.

Immediately after I made this change the upgrade commenced and was successful.

Hope it helps