"Call was canceled by the message filter" generally points to a third-party firewall blocking access to the client machine. Could you try disabling any firewalls present on the machine as a test and check whether you are successful in scanning it under these conditions. (Hit the Full Rescan button on the machine's Lansweeper webpage.)
Another option is that you scan the machine locally using LsPush instead, which should circumvent any firewall issues. More info on LsPush can be found on page 32 and beyond of
our online documentation.
