In the blog article The reason why re-installing software isn't a good troubleshooting method and what to do instead I discussed why re-installing software isn't necessary. I said that deleting the preferences usually is a better method for troubleshooting problems. However, you need to log out and log back in after deleting a preferences file.

The free app Prefs Editor from Thomas Tempelmann allows you to delete a preferences file with a couple of clicks.

When you open Pref Editor you will see this screen with a list of all available files:

PrefsEditor start screen

As there are a lot of files we use the filter in the upper right corner. You can filter for the app name or the company. There are no spaces in the names! We filter for "mothsoftware":

PrefsEditor filter

Select a file and click on the Open button:

Mail Archiver preferences

We get a lot of cryptic values in a - ahem - historically grown structure.

To delete everything do a Edit -> Select All from the menu or a Cmd-A. Then press the Delete button. There is no Save step in PrefsEditor! Everything is gone immediately:

If we don't want to delete the preferences values then we can edit, add or remove single values.

Click on the very small plus icon in the lower left corner. You will get this screen:

Mime_Sips is a secret preference value in Mail Archiver for a very rare bug with corrupt PDFs.  Mime_Sips is a boolean type preferences with only 2 values true and false.

To delete a value select the row of the value and press the Delete button or click the small minis icon in the lower left corner.

If you want to edit a preference value again select the row and then edit away:Edit value in PrefsEditorA couple of months ago I had a Mail Archiver user who forgot to remove the active value for an email client before removing the app from the computer. I couldn't fix the problem immediately. Instead we edited the "isActive" value here in the preferences.