reset application to its default state

Where are customized properties stored?

Application settings are usually stored either:

• in ~/.config/application_name
  Example: ~/.config/libreoffice
• in their own dedicated local (invisible, name starts with a .) folder in ~.
  Example: ~/.gimp-2.8

Furthermore, applications can have one or more settings in the dconf database (gsettings). A simple way to find out if that is the case is to run in a terminal window:

dconf watch /

...and play with the settings.

Lastly, (mostly) locally installed applications possibly created a local .desktop file. If so, you also need to delete that one to make sure you are starting from scratch.

Reset

Th bottom line is to remove these folders, if they exist, and reset the gsettings / dconf values. If you'd like a GUI way to reset thos keys, you can look them up in dconf-editor, and reset them to default.

Local settings folder(s) will be re- created on the next time you run the application.

dconf-editor is not installed by default. To install:

sudo apt install dconf-editor

Yes, you can. The method would depend on the particular application. You would have to find the configuration folder for that particular application and rename or delete it.

Many programs use use ~/.config/[app name]. For others, you would have to check with the particular application, or developers to get the folder name.

Some examples for instance:

Thunderbird:     ~/.thunderbird
Google Chrome    ~/.config/
Gedit            ~/.config/dconf/usr (This is configured via gsettings)
Wine             ~/.wine
ssh              ~/.ssh