I tried to launch the Unity Tweak tool, which had been working fine before, and it wouldn't work at all. When I do it from the terminal, I get this:

user@chrubuntu:~$ unity-tweak-tool
Traceback (most recent call last):
  File "/usr/bin/unity-tweak-tool", line 72, in <module>
  File "/usr/lib/python3/dist-packages/UnityTweakTool/__init__.py", line 79, in __init__
IndexError: list index out of range

How do I fix this?

3 Answers 3


Navigate to init.py file and edit the file

Comment file from line 79 to 89

It worked for me!

  • I am not very experianced so you might have to spell a few things out from me. LIke where is the file and what do you mean by Comment from line 79 to 89 Dec 3, 2014 at 2:38
  • 1
    nano /usr/lib/python3/dist-packages/UnityTweakTool/__init__.py Go to line 79 and comment till 89.
    – LostLife
    Dec 4, 2014 at 10:26
  • What do you mean by comment, I can open the file. Dec 5, 2014 at 18:44
  • Okay, I figured it out, but it didn't work. Dec 22, 2014 at 19:34

It says: "list index out of range". So, you could change 1 to 2:
1. executable_name=cmd_old.split('\x00')[1] //Change it
2. executable_name=cmd_old.split('\x00')[0] //to this

In order, to do that open terminal and type:

sudo gedit /usr/lib/python3/dist-packages/UnityTweakTool/__init__.py 

Then, go to line 79, executable_name=cmd_old.split('\x00')[1] will be there.

Good luck!

  • Where do you suggest to change it?
    – Pilot6
    Jul 18, 2015 at 20:13
  • I've updated my answer. Please, take a look at it.
    – rzaaeeff
    Jul 18, 2015 at 20:45

You guys were right, but I didn't know what to do. I copied and pasted this instead https://launchpadlibrarian.net/163835720/init.py

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