What I usually do is I keep on pressing return or enter until it opens, it usually takes like ten tries, if it keeps on closing, you could try restarting your Mac, but it is possible!
That’s strange. Did you try the command? I think it’s something like chmod +x *Drag the nwjs file inside the MacOS file that is inside the contents file, which you can find when you ‘check contents’ of the app by left clicking.* and it’s something like that, then it should allow you to open it, I’m no expert, though!