- Have you tried opening the actual .uproject file without the launcher?
- Do you have older engine versions installed? if you do, try and open up with an older version (right-click on the .uproject file and select “switch unreal engine version” and choose an older version. This will only work if you didn’t open the project in an earlier version.
- Did you try opening the launcher and verifying the installation?
Also, try updating the launcher version (if you have any orange small dots next to “settings”
Let me know if anything worked.