My code, (MCB2300 and RL-ARM) which parses a file on SDcard for execution commands, was working fine (theoretically) until today it's being thrown into the Undef_hander. If I make small modificatons to the source, it happens at different points in parsing, so it's not a hard error in the input. I can't find anything in the forums or docuementation on what throws this error. I've tried looking at stacks, etc. to no avail. It seems to happen in ftell() but I haven't pinned it down yet. Anyone have any insights?