I attach x-ref in one of the drawing......and then next day i open drawing is show but xref does not not show and i gives that message..............
Error: Possible circular reference to current drawing. *Invalid*
'circular reference' means both drawings are referenced in each other. to do that you need to do xref in 'overlay' mode instead of 'attach' mode.
so now to rectify the situation, open the drawing in question and change mode in xref manager in both drawings