Ae: videos not opening?

Hello, so I made this edit a few nights ago, and I wasn't finished so I saved it on Ae and logged off as I have usually done (and everything usually has been okay). However, the following day, I went to open the edit  (and I tried opening from Ae - open project AND straight from my documents, I opened it in as many different ways as I could), however it didn't open instead the following message appeared:

After Effects warning: unable to import file.

*name of my edit* as project (bad format or not readable)

I was furious (spent a while on this project!!) but was under the impression that these errors happen, so I looked at my 'auto-save' and found the edit. It was saved from a while back, so I basically had to re-make the whole edit. Then when I finished, I saved and logged off (as I have done before and nothing like this has ever happened) and now today, I am struggling with the same issue. This edit I re-made was saved under a different name, so I haven't accidentally pressed the old one! So the two edits ive made aren't opening... My auto-save is on, but as ive said, the auto-save only saved twice, so there was LOADS of effects I'd added that it had not saved, so it is naturally not helpful.

I'd really appreciate some help on this matter as it is stopping me from editing all together!

Thank you in advance to anyone who tries to help!