This error occurs when the production index (.CDX) associated the table has an index tag which has an expression which the BDE cannot evaluate. The solution is to delete the tag using FoxPro create an eqivalent index that the BDE can understand. The following conditions are not supported by the BDE and will cause "Invalid Index Descriptor" error. DTOC(, ) format not supported; Use DTOC(). ALLTRIM function not supported; Use LTRIM(RTRIM(Field)).