"Cannot open file "D:\Qimage Data\q.bmp". The system cannot find the file specified."
That is a the bitmap file of the grey "Q" that appears in the thumbnail area while a thumb is building.
Have a look in the Application/Program data folder to see if it is there. You can do this from the Utilities menu.
If not, does the old C-drive folder still exist and can it be copied or just re-install not forgetting to specify the D-drive location of the Application data as you do so.
It's odd that you have this error because that bmp is used every time thumbs are built, I assume that has happened on other operations after migration.
Perhaps Windows has locked the file in some way?
Terry