The message you're referring to is just a warning message and not quite an error message. It basically tells you to be sure you've selected the right bank before accessing the register. For example before accessing TRIS registers (in bank 1) you have to set RP0 in STATUS register. Of course you have to reset it afterwards (and for this you don't get a warning).
The assembler will put up this warning for each access to a register that's not in bank 0, unless you tell it to shut up (by setting the errorlevel).
BR