I had to reinstall macOS 26.1 today because of some wonky login issues. Ever since, I have been unable to successfully build my large project. The built app permissions are set correctly, but when I try to launch it I get the that unhelpful error – The application “MyApp” can’t be opened.
The bundle contents look fine, and the file in the Contenst → MacOS folder is shown as executable. I’ve rebooted multiple times. I’ve tried old versions of the project. I’ve tried reverting to an older version of Xojo (I’m using 2025r2.1). But although I was able to build before reinstalling Tahoe, I cannot now.
I should add that I can successfully build a Xojo example project. So it’s not Xojo per se, it’s something local that changed, added or lost, when the OS was updated.
Any ideas about how to figure out what is going on are appreciated.
You don’t mention how you fare running the project in the IDE. But after rebuilding your system, my first guess is a translocation issue. For this I would start by dragging your build folder (or entire project folder) to another directory, then back.
It’s similar in the IDE. I get the message something like “build failed”, and the .debug app that was created is automatically deleted. So it’s not a translocation issue.
I’ve just now tried disabling the file security in Terminal with sudo spctl --master-disable and allowing apps from Anywhere to be opened. Consistent with permissions being correct (i.e. not the problem), I get the same error message.
Look at your build settings and see if the architecture matches your machine. If you have an Apple Silicon machine and are building for Intel, you’ll need to install Rosetta 2… or build for ARM or Universal.
@Arnaud N I tried on an Intel Mac and it crashed, this time with a log. It says the code signature is invalid. But when I check the signing with spctl -a -t exec -vv or codesign --verify --deep -v, it says its signed properly.
I do have an entitlements file (embedded.provisionprofile), but that’s stored in the project and hasn’t changed at all.
It’s still unclear to me whether you tried on more than one computer and it crashed on each; if this is the case, it means the problem lies at build time. Otherwise, we can focus on the launch explicitly.
Can you run your application without codesigning (just for testing)? Can you show the exact crash log? Can you try to codesign one of the examples or some smaller project?
Thanks everyone for the suggestions. As luck would have it, a long-planned vacation just started. I’ll try some of these idea as soon as I’m back at the production computer.
@Greg_O@Beatrix_Willius@Arnaud_N Thanks for all your suggestions and help. I determined that the problem was indeed with codesigning, even though the various validation methods in Terminal said it was signed properly. However, when I removed codesigning step from the build steps, the app ran without a problem (on my machine). I then created all new certificates and edited the provisioning profile (which I needed for hardened runtime entitlements) to refer to the updated Developer ID certificate. Sounds easy, but it took a lot of time and googling. But in the end I’m finally able to build my app. I hope my experience may be of use to others in the future.