if cursorgetprop( [Buffering] ) > 1


cursorgetprop( [Buffering] ) not return a state for "Exists buffered records",
it return "Table support buffered records"

If cursorgetprop( [Buffering] ) > 1 is false your code return a error on TABLEREVERT line.

Use GETNEXTMODIFIED() AND GETFLDSTATE().