Comment 2 for bug 1155331

Can you run the following command in a terminal?

      dpkg --get-selections |grep unity-lens-files

It should report:
      unity-lens-files install

Does the output match? Your system seems to have the package unity-lens-files uninstalled. (That is my initial guess)

This bug is due to some section of code that is being rewritten to prevent bugs and for better maintainability.
I will try my best to fix the bug in less than a week from now. Thanks for your interest in unity-tweak-tool.

When fixed, the tool will 'grey-out' the settings that are problematic or missing and continue to function normally.