Bonjour: message 'Alerte'

I just upgraded DTTG 2 to DTTG3
The first sync seems me to be ok.
But now, when I want to activate Bonjour on my iPad, I get the following message:

"Alerte - la purge des anciens contenus a été désactivée car un serveur a besoin de données pour servir. Les bases de donnés partiellemennt synchronisées ne seront pas disponibles pour la synchronisation à partir de cet appreil.
Désactiver les connexions entrantes pour réactiver la purge - ok "

with Google Translate:
"Warning - old content purge has been disabled because a server needs data to serve. Partially synchronized databases will not be available for synchronization from this device.
Deactivate incoming connections to reactivate the purge - ok "

What should I do ? Disable? I don’t understand …

Not all files have been fully downloaded to your iPad but the Bonjour server needs the file data for clients connecting to it. However, it’s not recommended to enable incoming Bonjour connections on both the Mac and on e.g. an iPad. Enabling it on one device (usually the Mac) and connecting the other one to it is sufficient.

OK, I’ll do that. Thanks