I believe the one you want to double check is WWDR certificate. Note if you use Xcode to manage your provisioning profiles it handles all this for you.
You can check this by opening ‘Keychain Access’ and in your certificates section you would see a non-expired “Apple Worldwide Developer Relations Certification Authority”
To be fair they have little to no control over the signing process.
I launched an iOS app within the first 60 days of the app store. It took a week just to figure out how to build an app Apple would accept. There was no documentation or anything. It was absolutely horrid and that was with Xcode.
Ah ha! I’ve been waiting for this issue to come up. I’ve had the same problem since the installation of Xcode 8 a few days ago. I first started trying to find out what the detritus was and where it was deposited. There is a known problem with Xcode 8 choking on “FinderInfo” and other code fragments that get stuck in some files (particularly images) and there are ways to eliminate it via Terminal commands. I applied those methods to the post-build app package files and successfully eliminated that form of the dreaded detritus but it didn’t change the fact that the package won’t install.
In any event, I suspect the “detritus” is a red herring and have concluded that the real problem is not detritus but a failure of Xojo to code sign properly. You will find that the Xojo build process yields an App of appropriate size but which will not install. Attempting to do so with Apple Configurator 2 results in an apparently completed installation but leaves no trace of the app on your device. Installation via Xcode (devices window) fails with an error message saying the app isn’t code signed.
I’ve gone through the tedious process of redoing certifications etc. but the problem persists. The certs are confirmed to be ok because they work to install an Xcode-written app but have no impact on the Xojo Build problem. Very frustrating.
If you have 2016r3 installed and you’re on the release version of Sierra- you can Check for updates in Xojo Preferences to get a quick update to fix the “detritus” issue. Everyone with updates turned on will see it eventually but you can grab it now.
It’s a change Apple made in Sierra code signing that required us to change some things in return.