The technical reference lists some solutions to this error... I hope this helps. I copied it straight from the MAS 90/200 TRSG.
Error = 26 (Variable Type Invalid)
This error is MAS 90 data record-related.
MAS 90 Error Message:
ERROR: 26 PROGRAM: XXXXXX LINE: ####
Common causes may be:
1. The individual data record within the data file is damaged. This may be caused by a bad hard drive, a power
surge, or other operating system-related failures.
2. A numeric field is expected by the system, and an alpha field is encountered instead.
Possible solutions:
Caution!
Do not use the Rebuild Key Files utility to repair this error situation. Removing records from a file may result in an
“out-of-balance” condition in your accounting data. Record removal may also leave detail records in subsidiary files
without corresponding masterfile records. For example, invoices in the Open Invoice file may not have a
corresponding customer in the Customer masterfile
1. If the damaged record is in an index file:
• Delete the corresponding header record.
• Analyze and Relink Line Files.
• Rebuild the Application Sort File.
• Reenter the information.
2. Attempt to repair the record through DFDM or delete the record and reenter it.
3. Contact Best Software Customer Support Services for additional assistance.