Your maximum App ID limit has been reached. You may create up to 10 App IDs every 7 days. - Mobster

You see this: xcodebuild prints this as Communication with Apple failed while it signs Mobster’s helper. Mobster shows Your free Apple Account can make 10 app IDs a week.

Why it happens

Signing the helper needs an App ID, and a free Apple Account may create up to 10 in 7 days.

Fix

Wait a few days for the limit to reset.
Or choose a paid developer team in Mobster’s setup so the helper builds under that team.
Build again from Mobster for Mac.

Check it worked

The build finishes and mobster doctor prints no ✗ line for the runner. Checked 26 Oct 2026 against Mobster 0.4.0. Back to Troubleshooting.