I just checked our signing key and it doesnt expire until 2019. We definitely did have an expiration almost exactly a year ago on Jan. 27, 2014. At that time we renewed the key and pushed the expiration out until 2019.
After that renewal, we’ve only seen the error during upgrade via apt-get update. For some reason apt will cache the key and refuse to update it.
You can try to completely remove the EMS and then reinstall:
apt-get remove –purge evostreamms*
Or you can do a manual upgrade by downloading the tar.gz from our website and then replacing the binaries in your /usr/bin/ (you may also want to update your /etc/evostreamms/config.lua file!)
Sorry for the hassle!