Ah that's too bad that the backup file has the exact same problem.

You and Violet CLM are saying that some of the bytes are overwritten. How can you see that actually?
Do you compare it with a random level (not my level) to see which bytes were overwritten?

And about the Animations and Events, you say that they are intact. The level is completely empty but how about the Events that have animated tiles? Is that still visible or are only the Events visible?