Ue4 Problem

Hi, i have overwritten textures in a landscape material while the project was running. I did it several times but since i did it last time ue4 gives me big problems. No Matter what Project i have open now, ue4 stutters. Even after Updating to 4.26.2 and veryfing For example:

Map is loaded. I fly above the map with “w” and it stutters. If i press “space” while pressing “w” it sutters way less. The Problem imo is in ue4, not the project itself.

On my most important project i cant even move the mannequin anymore…rly need help

On all other project the character, while pressing “w”, is acting like i press “w” as fast as i can. on off on off etc, until i press “space” then its way better but is doing the on off thing again if i press “w” combined with “a” or “d”…

I work for my project like 10hour per day since a year help

Im using 4.26