When working with large expressions I sometimes mistakenly ask Mathematica to show some output which causes the front end to hang. Sometimes it just needs to format notebook contents but sometimes, it seems like it hangs forever. In both scenarios it would be handy if I could either

  • just save the notebook and restart the kernel, or
  • recover the data that is relevant and restart the kernel.

Is there any way to achieve this when the front end hangs?

I don't expect there to be a solution that always works (since the kernel might hang as well) but something in the form of opening a new notebook and starting a sub-session to recover some definitions would already be great.


1 Answer 1


There are three stages of "hang" depending on size of RAM of your machine and speed pf HDD or SSD.

  1. Working but not ending: Try Task manager to view CPU activity, memory use and HDD activity. If HDD is active and memory low you can stop by key "Alt+." or in the Evaluation menu

  2. Not responding to "Alt+." Try the Save menu or click right a Cell and select all cells by key "Ctrl+a" and try to save by a right click.

  3. If the Mathematica window stalls becoming opaque, try to kill the subkernel in task manager, but keep the notebook kernel running. Needs some experience, so on should train it first with some impossible task.

  4. No key or mouse working? Press power off 6 sec.


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