Preview pane not showing for Acrobat pro 12 (2015)-Windows 11 x64

Hi all,

Up till yesterday I had my preview pane showing the PDF thumbnails. When viewing windows explorer in icon mode, the PDF thumbnail shows up. However, the preview pane says "this file can't be previewed." 

I have tried a few common methods listed in this link,

The following did not work 

1. Acrobat > preferences > enable PDF thumbnail preview (was already checked, I unchecked & checked again) 

2. Tried using powertoys 

3. Registry editor

4. Cleared thumbnail cache

5. Even reinstalled acrobat pro 12 (2015), repaired installation 

Not sure what I'm missing here...