S300 -Could the project create Bus Failures?

Hi all, I'm quite new to this. Although I have some IT knowledge this is different stuff. I'm breaking my head over the following. I have SF and BF failures on the CPU. Checked all Profibus wiring A-B, FC connectors, addresses etc. which seems to be OK. I have uploaded a project via S7 Simatic.(MPI) So I can communicate but can't see all slaves due to BF failures. Now my question could the project influence Profibus and create Bus Failures?? If so how could I go back? Just delete all blocks of the project?

I don't think my question was that difficult. Maybe I should rephrase. Q. Do you need to download a project to get profibus working so that no BF alarms will appear??

Yes you need to save compile and download the hardware configuration!

All nodes that you have configured must then be powered up and match the HW config in order for the BF light to go out.

The CPU does not magically know the slave nodes that you have connected you need to add them into the HW config in order for the CPU to recognize them.

Check your terminator switches on the Profi-bus cable as well
note the IN - OUT cable points