Help, please - a recording is corrupted

Unfortunately, your screen shot does not show the parts that are missing.

Are you getting any specific error messages ?

There is a corrupt file recovery procedure here: Corrupt or Otherwise Broken Audacity Project Recovery, but I would not keep my hopes up that it will find anything other than what you already have.

Even before that, you could try Ctrl+A=Select All, Ctrl+C=Copy, Ctrl+N=New, Ctrl+V=Paste to try to copy the known data from your old project into a new, uncorrupted one.