After running sudo apt update and sudo apt upgrade ampinstmgr I receive a message that ampinstmgr is already the newest version (2.3.0.8)
Exptected to update to 2.4.5.0 as prompted by GUI
Actions taken to resolve so far:
not sure what to try
Your repo key is most likely expired.
Though that cannot be resolved until CubeCoder’s current TLS issue is resolved. (discourse is the only subdomain/site working atm)
Once the main site and getamp.sh are all fine again, run the following to update the repo:
bash <(wget -qO- getamp.sh) addRepo
Then from there you should be good to update as usual.
Though due to the age your install, you may need to update a couple times for things to be brought up to date fully, as the release system was changed awhile back.