QuickLook does not preview .txt files I have the problem that QuickLook does not allow me to preview .txt files, despite being plain text. For instance here



you see—no preview. Pressing Space does not help



However, Spotlight does show me the preview



How can this be? I am quite sure that originally, text file previews worked.
Could this have to do with MacVim being the default application for this file type? I am on 10.10.4 and have the following QL plugins installed:


BetterZipQL
iBooksAuthor
iWork
QLColorCode
qlImageSize
QLMarkdown
QLStephen
QuickLookJSON
Suspicious Package
Video
WebP
You're using the QuickLook Plugin with whatever app you've set as default to open text file. You can probably find that in Your_Application.app/Contents/Library/QuickLook.

As @Julien said:


  Generators embedded in applications are always preferred to plug-ins in ~/Library/QuickLook (which are preferred to the ones in /Library/QuickLook, which are preferred to the ones in /System/Library/QuickLook).


And there is no way to change that preference order. If you want to make sure it's the custom generator you can see the file with the default QL plugin with the following command in Terminal:

qlmanage -g /System/Library/QuickLook/Text.qlgenerator -c public.plain-text -p &lt;path_to_text_file&gt;


You can try to delete the app's QL plug-in, that could work but GateKeeper may stop you from opening the app, since it won't match it code signature.