"Sorry you are not allowed to view this file"

[MATTEK]

I'm confused...

First, you say:

There's about 7 users who have the issue. Different browsers with different operating systems.

Then, you say:

Nothing but browsers seem to be in common

They seem mutually contradictory, to me. 

Not all 7 of them have different browsers. A few have Mozilla, a few use IE and a few use Chrome.

Anyway, I fixed it. I was an issue with Aeva media.

[kat]

Coo! Who'd've thought?

Well sorted, Mattek and thanks for letting us know!