Did you update with the GitHub by any chance? There was a shader fault released in the update from yesterday?
Because it’s having a shader crash on your end with the default material for all objects in UE4 WorldGridMaterial, it could be the data it’s being parsed or it could be a faulty compiled shader or library fault. If you do a Verify you will revert to the old version of ADK and apparently the new binaries are “safe”