20-20 Worksheet: The file format was not recognized

A while back I was troubleshooting an error for a user running 20-20 Worksheet on a Windows XP machine. The user was one of many running the program, but had a specific issue opening sif files that no one else had.

If she attempted to open a sif file, she would get the file format was not recognized. Other users would attempt to open the same file and they would not have errors.

Like most technicians… I don’t have the patience to call other companies for technical support. So I sent 2020 customer support an e-mail and while I waited I decided to do it on my own.

I quickly downloaded process monitor and excluded all the crap. I opened the sif file and magic! It couldn’t find a few registry entries (HKCU/Software/Classes/CLSID and HKCR/CLSID). I went to a machine that was working and exported the missing keys and it fixed the problem.

Problem: Opening a .sif file within 20-20 Worksheet produced a “The file format was not recognized” error message.
Resolution: Import missing registry keys

…the best part is the e-mail correspondence between myself and “technical support”


What registry key did you import into her machine that fixed it?? And where in the registry did you find this key?


Sincerely, 20-20 Technical Support Team”