Comment 5 for bug 1584784

I can't seem to reproduce any such issue with Mir demo servers or Xmir. Old clients including Xmir work just fine when run against Mir 0.23 and lp:mir for me.

Admittedly I haven't tested the critical combination of Mir 0.23 + Unity8.

I expect you have too many variables though. When you upgraded to Mir 0.23.0 you probably also upgraded Unity8, QtMir etc. There's no telling which project contains the bug...