[Please deleate this-DoublePost] UE 4.26.2 - Missing cached shader map for material


I did update my UE to Version 4.26.2 some days ago.
Now, when I try to edit a material, the window frezes and nothing happens anymore.

Normally, I do use a different location for the “Derived Data Cache”.
Default is on C:, I do use a modyfied Version of the “BaseEngine.ini” inside my Project folder.
It does not work for both locations.

Did such an issue occur to someone else?
Please, might someone know a solution?

Please, do let me know.

Best regards.