Thank you. I had not seen the reference to build number. However I still need help with moidifying the "iCloud.com.example.apple-samplecode.SimpleiCloudDocument" line. What exactly do I substitute for "example", "apple-sample code", and "SimpleiCloudDocument"? Thanks!

Same problem here, App was compiling and working before Tahoe, Using only the default menu bar, Get many of these error messages, App also not working properly (main window not displaying), App still compiles and works properly on another Mac with same latest Xcode version but with Sequoia, Working App copied over from old Mac to new Mac says "The application <...> can't be opened. Really hoping Apple will fix this and magically solve this problem!