Hi Cuppacool, Welcome to the forums
I’ve seen this before when opening projects created in ‘future’ versions of the engine. For example, assets from a 4.24 project could be opened in 4.27, but 5.0 projects could not be opened in 4.27. (out of curiosity I just opened a copy of a 5.0 project with 4.27 and I’m seeing what you’re describing.)