Today I built an executable to put on the device, but here is what XCode says when I try to install :
Yesterday it worked.
What should I do ?
Just an idea, but try deleting any previous build before compiling the new version. I’m also now in the habit of deleting any old copy of the app on the device before uploading a new build.
No, that is not it. Deleted, built again, same punishment.
I posted the question before I reinstall all certificates and profiles, in case I overlooked something simple. Guess I will have to start over again 
Now after wiping out everything and reinstalling (certificates and profiles), it works on the iPhone but not on the iPad 
Apple utilities sometimes show this error when there is a mismatch between the profile on the device and the one the app is signed with. So I’d double check that the profile installed on your iPad is the same one on your iPhone, since that device is working…