Hi @khan28034583v3qt
Are you seeing missing thumbnails for your mogrts as well? or are you only getting the GDI Error?
Did you try deleting the ProBrowser folder as suggested earlier in this thread?
lear out the folder where the cached thumbnails are kept by deleting the ProBrowser folder.Premiere will generate new thumbnails on launch.
On mac: /var/folders/<>/<>/T/ProBrowser
Folders are in hidden libraries so for Mac:
Go to Finder > View
Hold the Alt / Opt key down to reveal the hidden Librari
...