Certificate Installation Error (iOS) - Profile failed to install. The certificate "AutoMDMCert.pfx" could not be imported.

This error is displayed on an iOS device during activation when a profile with the same file name already exists on the device.

 

Go to Settings > General > Profiles on the device and verify that a profile already exists. Remove the profile and reactivate. If the issue persists, you might have to reset the device because data might be cached.