>>>Usually this message appears when there is a filter on table having variables in the filter expression. If variables are not recognized anymore, then filter is cleared.
>>
>>In other words, it is internal VFP message. AFAIK none of our programs use SET FILTER (I'll verify). Do you know any other circumstances where this error can appear?
>>
>>Thanks a lot.
>
>There may also be a query where foxpro creates intermediate cursors or filters. Then the message may reflect the internal foxpro work where filters were not released.

Do you mean that there are some select into ... which create filtered sets? So far we're can not really find the source of a very strange error...