I have an Excel 2010 Workbook that I lock to USB's with a program called LockXLS. LockXLS works with 64 bit and 32 bit operating systems, and works with Excel 2003 up to Excel 2013. Sometimes however, (About 1 out of 5 or 6 computers) the program will not open on my clients computer. I have forwarded the error messages to LockXLS who assure me it is not a problem with their program. I get different error messages on different computers. Is there a setting in Excel that could be causing this problem?

Thanks!