One or more file aliases could not be resolved

I tried to open an InDesign file and a message pops up that reads 'One or more file aliases could not be resolved. Please verify that the file or files still exist and try this operation again.'. It also tells me that I last opened it 2 days ago which is not true, I was editing it last night. I save my files religiously whilst editing them, almost every time I change something so theres no chance that I just never saved the file. When I look in the finder at where it was saved, the file is no longer there, it also does not show up in search results.

The only thing which I think might have caused this problem is that overnight I downloaded quite a few films and I woke up to a message saying I had run out of disk space. Since then I have deleted the films to see if the file comes back but it does not. I have tried to access Time Machine but it tells me that I can only access a backup from today, another problem I can't seem to fix!

The only other posts I have seen about this problem is people who use CC on a school/college/uni server. I am using my own laptop but it might be relevant that I have been accessing the file using private wi-fi and Glide wi-fi, this is a service provided for students living in University halls. Currently I am in the University library and using Eduroam and this is the first time I have tried to access the file using this wi-fi. 

I have a deadline in a few days and I really need this file! Thanks in advance.