UDP silently blocked on MacOS 26

We have an app that uses UDP messaging. It has been working for over 3 years successfully. The App is now failing on installation with MacOS26.

The issue would appear to be that MacOS is silently blocking the UDP traffic. If we disable the local network for the App, and then turn back on, this will fix the issue. But this needs to be done on every system restart.

Answered by DTS Engineer in 894245022
But this needs to be done on every system restart.

That’s reminiscent of the issue we investigated here. In short, make sure you’re testing on macOS 26.5 or later.

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Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

But this needs to be done on every system restart.

That’s reminiscent of the issue we investigated here. In short, make sure you’re testing on macOS 26.5 or later.

Share and Enjoy

Quinn “The Eskimo!” @ Developer Technical Support @ Apple
let myEmail = "eskimo" + "1" + "@" + "apple.com"

UDP silently blocked on MacOS 26
 
 
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