>The help files say to call Microsoft if you experience this error. If you call them, they will tell you to re-index the program. I know this from experience... :-)
>
>Give that a try, it has worked for me on rare occasions where I have received this message.
>
>Also, raise a questioning eyebrow at the network environment that produced the error, especially if it is happening often.
>

Thanks for your suggestion! I did all that, but it turned out that the problem was on another place: In the Destroy event of a top level form I removed an object (THIS.RemoveObject("MyGrid"), and after removing this line the error did not occur anymore.

But your experience is good to know and remember.