TextMesh Pro TextMesh Pro breaks and becomes uninteligable in build only

I've been using TextMesh Pro in my version of unity (2018.2.2f1) for several years now, and suddenly when i make a new build all of the text becomes squares/unintelligible. Here is what it looks like



The text still looks normal in the editor and previous build, It should look like the image blow.



it's also not all instances of text mesh pro, as some are still absolutely fine in the build.

I tried making another build just in case it was a one off but it's still happening.
I haven't updated anything and nothing appeared in the console after the build completed. Any ideas as to what could have happened and any ides on how I could start to fix this?


Current settings for this particular font, these have not been altered for years likely.

 

Found the source of the problem, turns out my resources folder was over 4GB and that resulted in unity failing to build certain textures, removing some unnecessary/old files helped get it below the threshold. I will however likely need to look into asset bundles more