Try deleting the DerivedDataCache folder from the Engine install directory. Also, under Settings, disable any 3rd party plugins (ie. Substance) if open.
Also, in pre-existing projects, in the Project Folder, delete the Intermediate and Saved folders. Then, open the project, and select “Contents” in the Content Browser and select “Fix up redirectors…” and save project.
Fixed my problem with 5.4.3