Importing Standard Assets in 5.5 causes 'Unknown error when loading level0'

I have been pulling my hair out for the passed couple days due to my builds always reporting this error in a test project I was using. My project uses the following assets:

Advanced Foliage Shader
Suimono
TenkokuSky
TerrainComposer2
Standard Assets (Characters)

In a fresh project, I have added these assets one by one, making a build after I integrated each as I completely remade my project. Every build worked perfectly UNTIL I added the Standard Assets for Characters. Upon making a build that had this asset, I once again got the ‘Unknown error when loading level0’ message in my build. Even after deleting the Standard Assets folder, my project seems to be completely unable to make a working build now. Has anyone else had this issue? Is there anyway to fix this?

Welp after retesting and retesting… the Standard Assets are not the cause of this, it’s something else entirely. For some reason when I use three custom plant assets together, it causes this, even though they work when only using one asset at a time. I have no idea how or why that’s the cause.