Fetchmail (getmail) stopped working with errors like "offered message <id> but failed to provide it"

Recently, an external pop3/imap mailbox read by getmail stopped working after years of troublefree operation.
When debugging the issue, I found that it gave errors mentioned in communicating with the mail server (dovocot based ISP provided service). As this is an old ispconfig server based upon Ubuntu 14.04 LTS, it still used getmail version 4.43.0-1.
Simply replacing the getmail (and getmail4 dummy) with the latest version of getmail for the latest Ubuntu LTS fixed the problem.

Some help on debugging getmail:
* ISPConfig runs getmail every 5 minutes on the crontab of user "getmail". See "crontab -u getmail -l" (or replace -l with -e to edit)
* It runs /usr/local/bin/run-getmail.sh, which can also be called manually
* Add the option "--trace" to the call to getmail to show more debugging output
* Backup and then remove the file /etc/getmail/oldmail-<mailbox_id>* to read the whole mailbox again or add option "--all"
* Run a single mailbox with "getmail --verbose --dont-delete --trace --getmaildir=/etc/getmail --rcfile=/etc/getmail/<conf>" (the latter can be given multiple times)