The original project is damaged.

I tried to make a new project.

Try if it works by you. If have not the hardware (0BA7) for testing.

If the new project doesn't work, then have I bad news for you:
Then must you all complete new.

That I wrote. The project is damaged.

You are not the first with such this problem.

Have you original project load in LSC V8.3 and then saved?

I have exported the master cave program to single diagram (lsc). Then I make a new network projekt and insert the the two slave LOGO!s and then imported the master cave program.

Then I make the settings of all NIs and NQs new in the master cave program.