A few years ago I had developer certificates on another Mac computer running High Sierra where I successfully code signed my apps. They were in my keychain and in Xcode. All those certificates have expired. I was using maybe Xcode 9 or earlier. The latest version of Xcode that you can run on High Sierra is 10.1. I have resumed app development using a M1 computer since you have to be running macOS 10.14 or later to upload to their App Stores. I created new certificates using my Apple Developer account in my browser and installed them in the keychain. All certificates have been updated to Always Trust. When I run the following script: echo "Starting Signing..." codesign -o runtime -f --deep -s --verify --verbose "Developer ID Application: my corp (my id)" --entitlements ~/myappfolder/my_entitlement_file.entitlements "~/myappfolder/my_app/Contents/" echo "Signing app ..." codesign -o runtime -f --deep -s --verify --verbose "Developer ID Application: my corp (my id)" "~/myappfolder/my_app" echo "Verify Signing of app ..." codesign -vvv -d "~/myappfolder/my_app" echo "Done Signing..." I get the following output in my Terminal: Starting Signing... error: The specified item could not be found in the keychain. Signing app ... error: The specified item could not be found in the keychain. Verify Signing of app ... ~/myappfolder/my_app.app: No such file or directory Done Signing... I executed the following Terminal command: security find-identity -p codesigning ...and saw this output. Policy: Code Signing  Matching identities    0 identities found  Valid identities only    0 valid identities found I looked in Xcode 12.4 and my old certificate data that has expired appears when I click the Manage Certificates button in Preferences-Accounts. I can't remove them from Xcode even though I removed them from the High Sierra keychain and my Apple Developer account using my browser. When I do a right click on the expired certificate the option Delete Certificate is blocked. All I can do is Export Certificate and/or Email Creator. The only option I have is to add a new certificate. I can't do that because I already have active certificates. I'm not sure if it's checking my Keychain to say I have active certificates or not because I don't have any active ones in Xcode. I can't create a new pair of Developer ID certificates because I have reached the limit. By design they can't be revoked according to Apple Support. I contacted Apple Developer support about this but all I received was an email with a lot of links to go through. I have searched those links but didn't find any answers. After doing web searches I only found solutions for older versions for Mac and Xcode. I can't find any YouTube videos as the last 'customer support' representative suggested yesterday in yet another email with links. I don't know if the problem is related to old certificate data created in Xcode 10.1 that is a different format than the current data for Xcode 12 or not. I don't know the next step to take to resolve this problem.