How could be if a week ago was working? With these windows updates every day, i think yea, windows its problem. Just don't respond if you dont know how to fix it..
A "fix" can't be determined until the "cause" is discovered.
You've given no details on your system, or the OS.
Did the application get any update recently? Changed any hardware?
Rebooted the system recently?
Maybe the file in question is a format the application does not recognize.
Any other issues?
A failure of the drag and drop function is NOT a common Windows fail.