Unfortunately, you are telling the guy who is not in charge of the purse strings to spend money, which he has said he us trying to get done…but that doesn’t help now.
If the project won’t open at all, I’d guess it is a project resolution issue…too big for the free version. Usually if its a plug in, you get the watermark on screen, but the project will open.
I’d try opening the project in studio, change it to HD, export the project, and see if it opens. I’m not sure what the limitation size is…if uhd is allowed in the free version, but I’d start there.