Due to some problems with an old version of the core, I decided to update to commit 8516f8f (the latest).
Unfortunately, I found that when I stop and re-start Ryu as client controller, the core keeps on saying:
WARN | ol-21-thread-263 | CompositionManager | 186 - core.caos - 1.1.0.SNAPSHOT | 261 outstanding compositions
and the composition does not work anymore.
Any idea?