Invalid Long Address Number error on Purchase Order Header

Hi,

We are facing a weird issue in Purchase Order Creation and getting error "Invalid Long Address number" when we enter Supplier number (in Order Header). Same error for all the Supplier Numbers and no change applied to the related objects or no configuration change. We also can not create sales orders and getting error "Invalid Address Number" even for a valid Customer Number (for any Customers).

Any help is greatly appreciated.

thanks
Sathish