using Ubuntu 14.04

I have 1 files .crt extension. when I click to open , it open with view file application which displays the certificate information and other details which is fine.

Now I have changed the deafult application from context menu option Open With Other Application and set it to gedit and now can see the file content.

Now I want to reset the default open with the app by View file but there is no such entry in the list of Other Applications.

the property of the file is X.509 Certificate (application/pkix-cert)

Trial 1:

check cat /usr/share/applications/defaults.list but there is no entry for this type ofapplication/extension here

Trial 2:

Tried with ubuntu-tweak tool but there is no option to select view file application for this type of application.

Please help.

4 Answers 4


I am using Ubuntu 18.04. Right click the file → Select Property → Open With → Reset



I am using Ubuntu 20.04 LTS and for me the location of [Added Associations] was at


Before editing it is good practice to backup the original file and then edit. I used the commands as follows:

cp ~/.config/mimeapps.list{,_old}
vim ~/.config/mimeapps.list

Remove the certificate file related entries. For myself I had to remove

[Added Associations]

Then you can delete the old file if you want.


The default applicaiont is 'gcr-viewer'.

  • Hello, and welcome to AU! This would be more appropriate as a comment on the original question, as it doesn't provide a full answer. Thanks! Oct 4, 2020 at 6:37
  • Thanks, I was looking for the name of the application. Jul 16, 2021 at 16:25

Follow these steps

sudo edit ~/.local/share/applications/mimeapps.list

there is the entry

[Added Associations]  

remove above entry and also remove from [Default Associations] section and update the file.

nautilus -q can be executed after this if it doesn't affect quickly.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .