I'm having the same issue as well: looks like Emteria was compiled with OpenSSL 1.0.1f from 2014-01-06. Debian 10 user here; running OpenSSL 1.1.1. I could certainly create and boot into a live CD, then copy the AppImage over to it, but this seems like a pretty trivial thing to resolve, and it's been almost two months. At the least, please update the Linux installation instructions to specify any specfic OS- or distribution-specific dependencies like this.