LinuxQuestions.org - [SOLVED] Cannot install DEB's anymore on Bodhi 5.1 64-bit

I just used the terminal to install the updates for Bodhi.
I did it with this command:

Code:

sudo apt update && sudo apt dist-upgrade

Somewhere here in this forum there's some information about policykit-1 which is to be reinstalled, but it is already done and it is also in the start-up apps.

Then I remember some information about reinstalling eSudo, but I'm only offered version 1.4.0, which I guess, is the wrong version to support DEB's.

How can I install DEB's again by using a double-click on them, please?

EDIT:
Problem solved. I added a source which didn't fit there. Removing it, fixed it.