Im experiencing a similar issue where i cannot install any engine versions, install button is available click it then the Fab spinner goes gray for about 30 seconds then nothing happens then sometimes when i exit the launcher i get an UE4 crash screen with the same error listed above. Tried all forms of removing all epic content including a Rivo uninstall, reg clean, app data clean etc nothing worked. Got so fed up i just tried on my laptop that has never had any epic software on it and the launcher exhibits the same issue cannot install any version of the engine so i think its still BRICKED!!!