For me, problems range from slowness all across the editor. Editing shaders/materials and even material instances has become a major chore. Waiting an extremely long time after clicking the save button on material instances and master materials is a headache.
There are a number of slowdowns in the editor even with a clean or fresh install, new project, etc…
I heard on a livestream that 5.4.2 is in the works, hopefully it addresses the slow downs and endless shader compilation issues, the issues with packaging projects, etc… There also seems to be issues with duplicating materials in the content browser which causes a crash for me every single time I try.
EDIT: Duplicating isn’t the problem, the material itself was the problem. It failed an assertion in the D3D12Util.cpp… I can’t fix the material so now it needs to be rebuilt…
As 5.4 currently stands, the bad outweighs the good. I’ve been able to mitigate some issues by monitoring the UE5 repo and merging certain fixes or making changes myself. That’s far from ideal.