I am running UBUNTU 23.04 and trying to update it in order to upgrade tot 24.04lts. During the process I get several times the below mentioned error message. The upgrade is then aborted. Why do I get this error message and what can I do about it ? The error message :
The following signatures couldn't be verified because the public key
is not available: NO_PUBKEY 24A1004B1F11DCC9
The process aborts and then the next error message is displayed:
A problem occurred during the update. This is usually some sort of
network problem, please check your network connection and retry.
The number at the end of the message is always the same. I tried this:
sudo apt-key adv --keyserver keyserver.quickbuild.pearsoncomputing.net --recv-keys 24A1004B1F11DCC9
With as result: gpg: keyserver receive failed: No data
What can I try more?