Hello, I have a client tomorrow and he wants to fix some bad edits in melodyne on vocals on a live show (the track is 2-hour long) and also this tracks contains like 10-12 plugins or something like that from UAD etc. I freezed the track because it was very heavy on CPU (hundreds of melodyne clips) and freeze took about 30 minutes to finish..  but now I CAN NOT UNFREEZE IT! It crashes Sonar immidiately every single time after clicking "Unfreeze" button.. What can I do to avoid crash??? Can anybody help? I don't have a copy/backup before freezing...

The unedited, raw audio file should be in the "audio" folder.  Try loading the file in "Safe" mode. Create a new track, import the raw audio wav and recreate the plugins.
 
Hope that helps,  good luck.  Always save multiple versions.  Check to see if you had auto save or save multiple versions.  If not you should learn to use these. They are your best friend.

Maybe try loading the program in "Safe" mode and then hit unfreeze.  Say "No to All Plugins".

That file is rather large, so may be an issue reverting the Region FX on it. Is it possible that Melodyne was updated between the freeze and now?
 
Something to try. It seems the project opens, so open and immediately save as a a new project name (to the same folder). Add a new audio track and shift-drag that frozen clip to it (it will leave the Melodyne baked in), then ctrl-drag the FX from the original track down to the new one. Assuming most edits are good, you can then import the original audio as a new track so sections with "bad melodyne edits" can be swapped out for the same sections from the original as needed. Solo the dragged clip until you come to an issue spot, then split both tracks and swap the original in, and re-edit as needed. Not elegant, but should be feasible.

Best practice for the future is to render effects regions as you go. Not leave them dangling out there to cause trouble for you later. I do hope you get this sorted quickly. I ran a public studio for a while and it was a pressure cooker once or twice.