Crystal Report 13 display #### in numeric fields

Question

HEllo ,

I have migrated my Application from VS 2005 to VS2010 .
& crystal Report  10 to Crystal Report 13 version .

In some report, Crystal Report display numeric value fields as ##### . also if we check in old application it shows works perfact.
what can be cause of this ?
Also there is suffcient length in most of report .

Regards,
Yogesh