- occasionally EDNA servers can be stopped/crashed (warning window(s) appears noticing this and/or no more 1D curves are created): there are icons EDNA 1 and EDNA 2 on the left nela display, just click on them; 

- EDNA servers are running on sparta (2) and slavia (1) computers: they can be stopped/restarted also directly on them: ssh -X opd29@slavia (or/and sparta, psw), then type 'stop-tango-server' and 'edna-tango-server' on both computers to stop and start EDNA server(s);

- sometimes restarting also BsxCuBE will be necessary.

When for some reason slavia was down and restarted, one should restart sparta also but well after it (5 min should do).