This corrupt PDF thing happened to me also. Even though I don’t do screenwriting, somehow it showed up in a section of a large document I’m building.
I have a feeling it was due to a new iPad Air 4 being used (heavily enough) on the iOS side, but that doesn’t matter.
I tried a reasonable level of untangling the problem, without going so far as ‘clearing the font cache’. What I do notice is that Courier Prime is up to version 2.03 by now, which may indicate its maker recognized that there were problems. Unfortunately, it’s not clear that good old Windows is capable of catching up even if you install this.
Here’s something that turned up, though. This guy made yet another version, since he writes screenplays and found some heavy issues with early Courier Prime. I note that he not only solved issues including our present one, but has never had to re-release the font. Something even Adobe cannot say.
I put in Courier For The People, used itto substitute on the Courier Prime section, and got a very nice and clear pdf.
If yo u deal in printouts, or PDfs (which will embed this font so others never know) this may solve your problem, one could hope. If you share raw Scrivener projects, the others would have to install it too. But since that’s likely not a great idea for several reasons, maybe this really is a solution.
You’ll find there are two he’s made, actually. I didn’t try the ’ Little Foot’, as that is a little (probably too much) non-standard, though I appreciate it.
Last thing I could say is that Windows really can be a horror about fonts. Print shops know all about this…and so whether the problem here is about anything Scrivener development used or did, could very well not be so. And whoever did something, once it’s in the jaws of Windows, it may be very taxing to get it to let go. Thus the difficulty with answers…