Storyline 360 file is corrupted Help me to restore it.

Here is Articulate's standard advice: 

That is from this article about how to prevent corruption: Follow These Tips to Reduce Your Risk of Corrupting or Losing Project Files | Articulate - Community 

Unfortunately, if the above steps don't work, the file can't be saved. Ideally, you can update a recent backup version. If you don't have a backup, you'll have to redo the entire file. 

Hi shamkhan1,

Thanks for reaching out, and thanks to Judy for jumping in with such helpful guidance!

I saw that you also opened a support case, and I appreciate you taking that extra step. We’ve already shared an update there and will keep the conversation going so we can help you as quickly as possible.

If anything changes on your end or you find another version of the file, please feel free to add it to the case, and we’ll take another look.