Lightroom doesn't cause file corruption. Lightroom never writes to the image part of your photo files. This is how Lightroom works.
The corruption comes from elsewhere, most likely hardware malfunction or improper transfer from the cloud. You need to restore the files from your backups.
1. Can i disable sync in LR Classic, so it won't download my CC files from cloud?
2. Can i revert files from history in cloud? Like i can do on dropbox or onedrive?
- Yes, turn of synchronizing with the cloud by pointing your mouse at the nameplate, clicking the down arrow, and make sure that Sync with Lightroom CC is set to "paused"
- I don't know. Don't you have backups somewehre?
More info. After lr classic downloaded around 600 raws and corrupted around 30, it also deleted cr2 files from cloud. Only smart previews left.
Now i'm spending second day checking everything there.
What a facepalm interface / programming adobe. Shame on you!