My experience from over 2 year of working with Avast in conjunction with the hub:
1. Customers who can't install the client using a specific global policy. He needed to use another policy, than it worked... Until today it was only one customers out of 84 that had this problem.
2. Clients that have problems executing tasks comming from the hub. Theses tasks will just got stuck in the clients tasks view of the hub. Troubleshooting with Avast support resulted in Error 6020 --> -
MessageProcessor::netCarrier: HTTP Status [400], request len [495], response len [53], url [http://bconsole-avm-pro-ams.ff.avast.com:80/handle]- PlgMngtic failed >
http://bconsole-avm-pro-ams.ff.avast.com:80/handle< Proxy[0] rc = [-3]
In those cases the Avast support comes with standard advice to check the firewall settings.... Yes thats anoying since you always get the feeling that theses think you are a dumb end user...
Anyway the solution for the 2. problem was just a reinstallation. After that the client was cleaned up, and new tasks where sucessfully executed.
Problem with this is that the hub will loos the entire history of task, also installed patches...