saving material asset stuck on 50%

Decided to rewrite my question here…
the problem: material assets are stuck on 50% and it takes a very long time before I can continue to work on the project.

At first, I thought unreal just crashed but it turned out it just takes really 15 minutes or an hour in worse case.

The asset itself is just a few KB on the HD so this all makes no sense. Currently the only way to get around this is to put all complex stuff into a material function and keep working on that. Saving the material function is instant done. All material assets have this problem. I also tried to run a new clean project and put a clean material here and just hit save. It again takes a few minutes to save the material asset.
What can we do about it?
regards! T

old:
So…I have been trying to save a material asset for just an hour right now…and unreal just keep stuck on 50% saving. Forcing me to restart the engine and do all the work again.
What is going on here?
Why does it take ages to save an asset? (unreal 4.11.2 btw)

regards! T

Same problem here. 4.12. I am using an external USB drive. I’m wondering if this is a cause.

Have same problem after I transfered to Windows 10. Material saves last 5x longer, progress bar is stuck on 50%.

I’m experiencing the same problem (version 4.13 and before). Maybe this is related to shaders compilation, but I’m not sure. Looking for a solution.

Nevermind, the problem appears only of FPS template project… In empty project all is Ok. Of course, that strage, but at least I can work, good luck!