Hi Dneuwir,
We too have experienced this many times, and in our environment we've narrowed it down AV software most of the time.
On client machines in which we attempt to install KVNC or similar for Remote Control, it just fails without explanation.
When further investigated we discovered, the kvnc install package is downloaded into the Kworking directory and then the Agent attempts to run that installer package; however, the AV software on the computer was preventing/blocking the exe installer for KVNC from running.
It's not pretty but we've since had to implement a policy in which when we install the agent on a machine, we add exceptions to the anti virus software for both the kworking folder (main exception that is needed) and also the kaseya agent install folder (which would include the AgentMon process)