The uploaded version of the project was created from the Standby PLC. Word 81 represents the unit address, so the PLC project will be seen as unequal
when connecting to the Primary PLC which is using the rotary switch address rather than the offset address.
Another possibility could be that you do not have all of the appropriate patches for Concept 2.6 SR2. There are 3, patches A,B and C.
Please find the below link for patches