>HI Mark,
>Thank tou for your help. I did what you said and I still get the same error (C000..5 and VFP crash).

Could you test by creating a completely new form with a grid and combo? Don't duplicate what you already have, just keep it as simple as possible. If that works, start adding other components that are in the other form and test as you go. There is something else going on that would cause this. You may want to quit VFP, move your current Foxuser.dbf and .fpt to a backup folder and start with a fresh foxuser file as well.