Upgrade to 8 compiled with a different version error

I upgraded to version 8. My project fails to compile with the following error:

[dcc32 Fatal Error] fClientDataModule.pas(8): F2051 Unit uROServiceComponent was compiled with a different version of uRORemoteService.TRORemoteService

I probably need to recompile something, but I need some guidance.

Delphi XE3

Issue appears to be solved. I removed the unit from the uses clause, and everything appears to be working.

this unit was empty and was removed from RO8. look like you have uROServiceComponent.dcu somewhere in library paths.