Update of LyZ that should improve connection to lyxserver on linux (and possibly Mac too). Thanks to Johannes Schwarzer for pointing me to an easy solution. There is a new preference setting: extensions.lyz.os, which should be set to „Win“ on Windows and „Linux“ on other platforms. After installation, please navigate FF to about:config and check that the variable has been set correctly. Mac users, please let me know if this version or rather the previous one (2.1a1) works for you.
Please download LyZ 2.1a2 and let me know about any issues.