Premiere pro, media encoder and mojave. Constant crashing.

Very similar issues! Cannot export in h.264 and extremely disappointed in Adobe's customer service. Save the snark Adobe, it's not cool, we are experiencing very critical issues.

Brendan,

I upgraded to premiere pro 2019 and Mojave around the same time (individually, bad ideas... done together: career suicide).

Agreed. Avoid these avoidable errors in the future.

Ever since, I get a repeated crash and unbelievable slowness. A dialogue box asking me to repair creative cloud, endless beachball, the works.

You updated a major project from one version to the next in the middle of a project? That is equally not a very good move. Adobe hat off, this is my opinion, of course.

I have resorted to using PP2018 and not using media encoder at all.

Moving back to the project format you were working with is a good move, IMO. If you must absolutely use the new version with your old project do the following:

1. Create a new project
2. Import the old project into the new one.

You will find more success in project stability by doing so.

Time was, apple didn't release things in major technical debt. Neither did adobe. Those days are gone.

Not sure what this means.

Now they force their customers to do their R&D for them, while having to pull all nighters and late hours due to this crap. All for the low low price of $50 a month.

I wouldn't say that, but I hear your frustration. I'm not having your issues with my personal projects, but I do not update projects midway through them. I think that is the main problem in your workflow. Finish projects in the version that you started them in and you won't have this issue in the future.

Adobe, when are you going to release an update that debugs everything and gets out in front of Apple's Mojave nightmare?

I think you already know that Adobe and Apple are two different companies that do not always operate in perfect sync in our product release cycles. If you stick to some basic rules of thumb, like the ones you mention early in your post, and the one that I mentioned, you will have a much more solid and predictable experience with these products.

One other small piece of advice is related to updating macOS. Whenever you update the OS, perform the following steps to make sure that your Adobe folder permissions will work will with the new version of the OS and Premiere Pro.

Please let me know if I can help streamline your workflow further so that you have the best possible experience.

Thanks,
Kevin