The [EmDebian project](www.emdebian.org) is closed and the repository is not available anymore ([read more...](https://wiki.debian.org/Embedded_Debian)). To continue to use it on your Acme Systems boards delete this file on your microSD:

/etc/apt/sources.list.d/multistrap-emdebian.list

Then type:

# apt-get update

After that you can install or upgrade any package.