I have this same problem with a project that was running / building fine (Swift MacOS app on M1 Pro Xcode 13.2.1) until I did all the necessary configurations to upload the app to Test Flight. Now I get this message. Have tried the signing and build folder clean options mentioned in this thread. No luck. It's a show stopper for me. If I can't resolve it I'll have to create an entirely new fork of my project that I never use with Test Flight. Don't see any other option at moment.

I have same problem with no fix in sight... Apparently, a recent MacOS (M1 MBP) update included some kind of Xcode update and literally everything I've read online and tried hasn't helped. I'm Dead In Water and my app UI / storyboard is too complex to try and re-create from scratch without investing a LOT of man hours although that might be literally the only solution at this point. This is a show stopper for me. Literally no clue what else to try at this point.

Does this forum actually worked? I've posted 2 replies and both haven't been posted to this thread... If this one works, my question is how would I know if this Electron app is sandboxed? And, either way what would be the remedy if it is or isn't...?

Thanks Eskimo. Alright, let me see what I can do. Syslog can work. However, does this (to your last point - "Your app's bundle is effectively read-only...") rule out using things like embedded SQL (sql lite) db's for Mac apps? I'll read the docs you referenced, 'preciate it

Thanks, ok, noted. I'll do some homework... Actually, the only reason I built my 1.0 with Electron is bc I had built an entire (my first) MacOS app with Swift to host WkWebView and then some Xcode update happened and my entire Storyboard broke. I tried to figure out the issue and it was over my head and didn't want to re-do the entire month of work it took me to design that Storyboard UI... So, I punted and moved the app to Electron (which sucks in so many ways but it's stable and covered all the platforms I needed like Apple Silicon/Intel, Windoze, Linux, etc). But, honestly, I know I have to go back and re-build my MacOS app and eventually ship using Swift for the Mac version of my app. I just didn't / don't have the time for that at the moment. I would not classify my "first app build" on MacOS with Swift and Xcode and Storyboards to be gentle or all that productive... But, I learned a lot. And in the end, I may just create C++ cross platform base to all my apps bc I'm more comfortable doing that anyway. Swift is eh.... Frankly fairly cryptic IMO... Thanks for all the help. Launch soon, wish me luck