My front-end freezes as soon as I type more than two letters in a notebook. I think the error occurs, when the auto-complete feature kicks in. If Mathematica was started from a terminal, the following text is shown.

Mathematica has received the signal: SIGSEGV and has exited.
If possible, please report this problem to [email protected]
describing in as much detail as possible what you were doing
when the problem occurred.

I use Mathematica 10.3 on Ubuntu 12.04. Rebooting and -cleanstart did not help. This installation worked fine for quite some time, but suddenly this problem appeared.

Is this a known problem? Before I contact the official support, I want to make sure that there is no trivial fix.

  • 2
    $\begingroup$ @StefanR You were right, CodeAssistHistory10.3.m was 321MB big! Removed it, everything works. Thanks! $\endgroup$
    – murphy
    Commented Mar 3, 2016 at 19:25
  • $\begingroup$ @murphy good to hear! Sorry you ran into this! $\endgroup$
    – Stefan R
    Commented Mar 3, 2016 at 19:27
  • $\begingroup$ @StefanR Maybe you should add your comment as an answer. That would make it more future-proof and I could close the question. $\endgroup$
    – murphy
    Commented Mar 5, 2016 at 11:42
  • 2
    $\begingroup$ I have just noted a similar behavior on 10.4 (Win 10 Pro), where all text inputs after two characters suddenly stopped as can bee seen in this capture of the problem. Unfortunately I was pointed to this post too late - I am just reinstalling Mathematica... $\endgroup$
    – gwr
    Commented Apr 18, 2016 at 17:51
  • $\begingroup$ See also this post asking for bug reports including the CodeAssistHistory files for better diagnostics of this problem and hopefully a fix in the future. $\endgroup$ Commented Apr 24, 2016 at 18:17

1 Answer 1


(Posting my comment as an answer, per @murphy's suggestion)

Please check the folder


and see if there are any unusually large files there (>100 Kb or so). If any such files exist, please delete them. The file CodeAssistHistory10.3.m is often the culprit, and is safe to delete.

  • $\begingroup$ Are there plans to fix this? My CodeAssistHistory10.4.m is also huge (25.2 MB), and most of it is just a bunch of ÂÃÂÃ... $\endgroup$
    – QuantumDot
    Commented Apr 14, 2016 at 13:07
  • 7
    $\begingroup$ @QuantumDot we believe we have a fix for this in Mathematica 10.4.1. $\endgroup$
    – Stefan R
    Commented Apr 15, 2016 at 16:52
  • 2
    $\begingroup$ I can confirm that this solution works with regard to my above comment. My CodeAssistHistory10.4m had a size of 712 MB at the time of deletion. $\endgroup$
    – gwr
    Commented Apr 18, 2016 at 18:58
  • $\begingroup$ Thanks a lot for this! My file was 1.5GB in size at the time of deletion! $\endgroup$
    – Prahar
    Commented May 12, 2016 at 20:24
  • 1
    $\begingroup$ This didn't work for me. I didn't have any files of the form Code* in my FunctionalFrequency folder, and none of the files were over 18 MB. I deleted all the ones over 100 KB but the problem still persists if I enable autocomplete. $\endgroup$
    – tparker
    Commented May 17, 2016 at 3:43

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.