Error jessie InRelease

Hi, my openhab 2.3 snapshot runs on a debian server.

Since few days i get the following error, when trying to make an apt-get upgrade:

W: GPG-Fehler: jessie InRelease: Die folgenden Signaturen waren ungültig: KEYEXPIRED 1515017477 KEYEXPIRED 1515017477 KEYEXPIRED 1515017477

Here is the exact same problem described with a way to solve this, but i lack of linux experiance to do that…

Please can you tell me, how i have to do this?

–> remove the repo and use the latest in jessie or upgrade to stretch

I already made this:

sudo apt-get update
sudo apt-get upgrade

sudo apt-key add mosquitto-repo.gpg.key


apt-get-update / upgrade

/// then i made:
sudo apt-get dist-upgrade


/// but still the same errors

Is there anybody, who can help me? The error still exists…

My openhab and mosquitto is installed on my debian jessie server.

try this:

$ apt-key list


pub   4096R/30993623 2013-01-04 [verfallen: 2018-01-03]
uid                  Mosquitto Apt Repository <>

keyID from mosquitto is "30993623"
After this:

sudo apt-key del 30993623

key removed.
Now get the new key and store it:

sudo apt-key add mosquitto-repo.gpg.key

no reboot needed
Now you can do apt-get update again.

Thank you. Now id did something when i made apt-get update and upgrade.

But the error still apears, when i make apt-get update again. Even after reboots.

perhaps you have more than 1 key, which isn’t valid anymore…read the log carefully.

I don´t need mosquitto (MQTT Server). I installed it only fore testing some time ago.

How can i completely remove the mosquitto-files including all other installed things (in german: inklusive aller damals mitinstallierten und dann nicht mehr benötigten Abhängigkeiten)?

I made

apt-get remove mosquitto

and after that

apt-get autoremove

to remove the dependencies, which are not needed anymore.

After that i removed the repo key also like described from you a few posts above.

Now i get this when i make apt-get update

W: GPG-Fehler: jessie InRelease: Die folgenden Signaturen konnten nicht überprüft werden, weil ihr öffentlicher Schlüssel nicht verfügbar ist: NO_PUBKEY 61611AE430993623

I found a thread in the internet where this was descripbed to do:

gpg --keyserver --recv 61611AE430993623
gpg --export --armor 61611AE430993623 | sudo apt-key add -

After that i made apt-get update and the error is gone.

But now the mosquitto-repo-list is there again when i make apt-get keylist.

Is this ok or should i remove the mosquitto-repo?

How can i do this?

I have no clue, what this commands did… I´m a linux beginner.