The system runs periodic Cron jobs to prefetch updates but has recently run into the following:
CRON-APT RUN [/etc/cron-apt/config]: Thu Jul 8 00:06:09 EDT 2021
CRON-APT SLEEP: 2144, Thu Jul 8 00:41:53 EDT 2021
CRON-APT ACTION: 0-update
CRON-APT LINE: /usr/bin/apt-get -o Acquire::http::Dl-Limit=25 update -o quiet=2
E: The repository 'https://dl.bintray.com/openmed…plugin-developers/arrakis stretch Release' does no longer have a Release file.