The following signatures were invalid: EXPKEYSIG 18DF3741CDFFDE29

[Ralf Mardorf]

On Mon, 10 Jan 2022 13:38:04 +0100, Liam Proven wrote:
>On Mon, 10 Jan 2022 at 08:45, robert rottermann wrote:
>The repo signature is no longer valid.

Hi,

obviously the key expire was extended. After taking a look at the
current available key, I can only do an educated guess.

"$ gpg --show-keys DEB-GPG-KEY 
pub   rsa2048 2017-12-19 [SC] [expires: 2023-12-17]
      D56311E5FF3B6F39D5A16ABE18DF3741CDFFDE29
uid                      philandro Software GmbH <info at philandro.com>
sub   rsa2048 2017-12-19 [E] [expires: 2023-12-17]" -
https://lists.ubuntu.com/archives/ubuntu-users/2022-January/306500.html

Much likely the key expires each year in December and then gets
extended. My guess is, that if the OP does update the key, everyting
will be ok again.

At least I avoid using snaps and recommend to install a regular deb
package instead. I don't have a clue how e.g. this particular remote
desktop software does authenticated or if it requires interaction with
whatsoever software. Snaps are asking for trouble, if communication
with software outside of the snap "container" is required. There are
tons of examples, such as semi-working email clients. To my knowledge
snaps are the way most abysmal among all those alternatives (flatpack
etc.) and it IMO is the very last alternative to recommend, especially
if a regular repository is available.

Regards,
Ralf