My friends:

You both tell me how to manage the error... But I want to know WHERE THE ERROR IS!!!

The idea of a stack in destroy event I promise I will study it but I said too that was an example.

Two problems together:

1) A table or cursor that must be opened is close

2) An object that must exists doesn't exist. (but the form object apparently exists)

Memory? I think about memory but I DON'T WANT TO THINK it is memory!!!

I wouldn't know how to manage that kind of error. I don't open hundred of tables or cursors, I don't declare thousands of variables

In fact (in the example) I do a loop (figured) The user appends a record in the cursor, opens and closes the same table to read records and doesn't append hundred of records, just a few.

I don't know but I thank you very much

Héctor