Hi! I am fairly new to Mac/ Python development. I have written a python script that includes the lovely customTkinter Library. the app works, I have checked it extensively, but after creating an executable with both Pyinstaller and Py2app, my app keeps failing notarization. I have the developer account, I have the Developer ID application: Name (xxxxxxxxxx). My last attempt with py2app, I try to codesign the .app bundle with : codesign --deep --force --verbose --options=runtime --timestamp --sign "Developer ID Application: Lennert Esser (5823RMSZ52)" XYZ\ 2\ OSC.app if I do that, I receive a clean message that XYZ 2 OSC.app: signed app bundle with Mach-O universal (x86_64 arm64) [com.myname.appname.app] the verify of the code signature gives nice messages as well: --prepared:/Users/lennert/Documents/SoftwareDevelopment/PythonLocal/Pozyx/dist/XYZ 2 OSC.app/Contents/MacOS/python --validated:/Users/lennert/Documents/SoftwareDevelopment/PythonLocal/Pozyx/dist/XYZ 2 OSC.app/Contents/MacOS/python .... XYZ 2 OSC.app: valid on disk XYZ 2 OSC.app: satisfies its Designated Requirement So I would say, so far so good...? BUT.... if I try to notarize my archived .app bundle. the notarization fails, with looadddssss of errors, with both: "The signature does not include a secure timestamp." and "The binary is not signed with a valid Developer ID certificate." I am completely stuck. Believe me, I have tried everything. Google, ChatGTP, multiple tries to codesign everything separately with: find /path/to/my/app/contents -type f -exec codesign -s "Developer ID application: Name (xxxxxxxxxx)" {} ; please, please someone help me explain what I am doing wrong....