Edgar,

"If you hear hoof beats, think horse not zebra."

Find out which cursor record 21 is referring to. Go into the data environemtn for your form and look at the Order property for that cursor. It is most likely set to a non-existant tag. Double, not tirple check the spelling of the tag name. use the drop combo to select a tag fomr the list of available tags.

VFP is giving you specific information about the error, it is being asked to use a tag that doesn;t exist. Something is asking it to do that. If the cursor looks ok, then check teh methods of teh DE, OpenTables etc.. to look for any code that is SET ORDER on a table or USE Table ORDER commands.