You double-click a file (a PDF or FM file, for example) and receive a message such as
Cannot find the file 'c:\whatever.pdf' (or one of its components). Make sure the path and filename are correct and that all required libraries are available.
Other programs may issue slightly different messages. For example, Frame asks you to make sure the file exists.
This seems to happen mostly on files that have a space in the file name, or that are in a directory or a path to that directory that includes at least one space.
After acknowledging the message, the file may or may not open anyway.
The steps below are written for PDFs in Windows 2000, but the theory is the same for other files and other Win 9x operating systems. In other words, the buttons or the order in which you click them may vary:
"C:\Program Files\Adobe\Acrobat 5.0\Acrobat\Acrobat.exe" "%1"