Nothing mysterious about that. It all explained in the article I pointed you to.

>Interesting. All I had to do was to add an ORDER BY clauses and I was suddenly able to index the file, but when it is a single table and no ORDER BY clause exists, you must add the READWRITE clause.
>
>Thanks Sergey!
>Cecil
>
>>Add READWRITE clause to make cursor updateable and check http://www.berezniker.com/content/pages/visual-foxpro/queries-and-filtered-cursors
>

>SELECT * ;
>	FROM GRPEXTCV ;
>	INTO CURSOR tmpGRPEXTCV READWRITE
>