Hello,
Yesterday I got info from one of my colleagues that he was able to launch the 5.2.1 with the solution described above by EngineDevRob.
There are steps he mentioned:
TODO to fix the problem in 5.2
1. Download Unreal Engine 5.3 from zip
2. Copy ShaderConductor directory from \UE_5.3\Engine\Binaries\ThirdParty
3. Paste the directory in the same place in EU5.2
I can also share the file if you need it. I haven’t tried the solution yet but for him, it works without issues. At least for now.
UPD:
I tried the solution and it does work. Our team currently work on the 5.2.1 production version of the engine