when ever i start up the demo i get this error which leads to me not seeing anything 
Viewing post in BBG - The pleasure of the fight v 0.5 DEMO +VR comments
if you see something like the background overlaying everything then it's because UE5 needs latest drivers on the GPU but it depends also on the GPU kind. if this is your case i had this problem on other 2 users, one of them tried it on another computer and it worked.
also, the launch can take some seconds on black screen, time to load important things