Yesterday I updated my Macbook Air (early 2015) to macOS Mojave.

Since then when I open a terminal window I am getting recurring messages. I can't run any terminal command at the moment.

What can cause this message?

enter image description here

  • can you stop it with control + C
    – Ruskes
    Oct 20, 2018 at 7:37
  • No, it does stop it for a little while. Then it starts again.
    – JohnShape
    Oct 20, 2018 at 8:12
  • What do you mean by that? I am an admin user, is that different?
    – JohnShape
    Oct 20, 2018 at 16:02
  • Thanks. But it's a bit strange. I can't see the option Join or Edit in the preferences screen. See: i.stack.imgur.com/CnZ85.png. Are the instructions on the Apple site old?
    – JohnShape
    Oct 20, 2018 at 17:24
  • Oh I didn't look well, it was a language issue. The Dutch words are a bit different. This helped as well. youtube.com/watch?v=mA3CuWQ56_4. But Root user is turned off at the moment. Is there a proces I should end in rootmode?
    – JohnShape
    Oct 20, 2018 at 17:35

1 Answer 1


Your system is running something called the Malloc Debugging and reporting a problem in your memory ? It is a program to detect memory bugs. Since it is stuck in a endless loop, the reported memory bug might not even exist.

It reports the same bug in your memory, over and over as seen here.

enter image description here

More info about Debugging memory-related bugs


To stop the program in Terminal try Use key combination in Terminal Ctrl + C. or, Ctrl + Z , or CTRL+ \

You can also try...

Simple test is to start in Safe mode, or even more simple is to create new user account and try it.

  • Thanks for your answer. I don't think there is a problem with my memory (I did a diagnostic with hitting D while starting my laptop). Some googling tells me that apps or processes can give errors, like this. I think this is coming from 'mms'. Activity monitor says mms is part of launchd. I am guessing that a program running in the background is causing this. But I am not sure which one.
    – JohnShape
    Oct 21, 2018 at 9:23
  • mms is just message format (Multimedia Messaging Service (MMS) is a standard way to send messages, and that mms it is actually telling you that the program called Malloc is reporting a bug in your memory. The standard hardware test with D does not do in depth RAM test. The Malloc program is stuck in a loop and not responding. Did you manage to shut it down as per my instructions.
    – Ruskes
    Oct 21, 2018 at 15:47

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