Not allowed to edit my own music video?

I'd recently encountered something peculiar, which I don't understand and could very well put a stop to my music video and it's finalisation.

On the last week of term in one of my lessons, I went to edit my music video (obviously). To open this, I need to locate the scratch disk named "The Gospel Of John Hurt" on the Mac. This then directs me to FinalCutPro and editing can begin once my film has loaded. Without a scratch disk, a film can't be made/saved/editors (you get the idea - no disk, no film). Anyways, as I clicked on my specific scratch disk "The Gospel Of John Hurt", I was greeted with something I wasn't necessarily predicting.

"You dot have the right to open this file/view this file" (probably isn't a 100% direct quote of what was displayed, but I'm 99% positive).

I don't have the right to view this work? Huh? This is MY work. I created this. Without me, there wouldn't be this stupid message coming from the scratch disk that I myself created.

I clicked and I clicked and I clicked and the same message greeted me every time. So what now? I can't edit my music video, that's what. Even worse, what if my music video isn't there anymore? It may just be me being an absolute donkey and a pleb and not clicking on something initially which allows me the right into FinalCutPro and my video, or that I'm just clicking the wrong thing or any other stupidity factor that can happen to someone who was too tired to concentrate at that moment in time.

Considering the deadline for the draft was Christmas, I'm having a crisis...as you can see...no film. As its only a draft which is needed, I'm hoping that my teacher (being the goddess that she is) can allow me that little extra week or so to resolve this, or in the worst possible case...to re-film and comprise it into a music video ASAP. I'm hoping it doesn't have to come to that because as I said, it may have just been me doing something idiotic and not selecting the right thing (which is probably the case).

Only time will tell when I go back to sixth form at the beginning of January and see if I can revive my music video from the deepest depths of a Mac...

If not, I could always just take some selfies and put them together as a collage. That always works.