Multi-tasking computers (receiving faxes, downloading email, performing background virus checks, working on other processes) being interrupted during crucial write processes, power interruptions during write processes, muilti-users accessing the same data at the same time, multi-users writing to the same record at the same time, hardware aging (power supplies & filters glitching, the surface of your harddisk wearing and thinning, other circuit boards faulting, etc) can all contribute to corrupted data files.

This problem is especially acute for companies running P3 on networks with many simultaneous users. Btrieve was never intended to control more than a handful of users at the same time. This was a major driver for big companies to switch away from Btrieve (P3) and go over to the dark side (P5) which uses a much more sophisticated multi-tasking database server/manager platform.

There is also the possibility of your schedule data files being corrupt. Try running the Primavera file correction utility C:\P3Win\P3PROGS\PFXW.EXE on your schedule to see if that is the problem. The help button in the program will tell you how to run it. Good luck!