I was first thinking that JCS did change some bytes when opening a level. But that is now absolutely not the case.

You can only see the codes and compressed codes etc. because JCS refuses to open the level. How can i restore the most of this file if i can't open the level?

And i have looked around on all files on my computer and USB's but didn't find any corrupted files. The only thing that is corrupt is this level AFAIK.
I will try CHKDSK tomorrow and will place the results if it works.