It is referring to a Hyper-V host that isn't monitored by Virtualization Manager. It was monitored before, but not anymore (the Virtualization Manager in use is a GA that has been upgraded to RC1).
When i click Open Virtualization Manager, i get the following:
As you can see, there is NO Hyper-V host in the Data Sources. As far as I can tell, the issue here is either:
VMan still has some sort of data belonging to the Hyper-V host that it once monitored, which explains why the IVIM synch still thinks that the host is monitored by VMan and that is why the Synchronization is not completing. One would have to "flush" the Hyper-V details from the VMan database, or something.
OR
2. You are not able to Synchronize Orion and VMan unless the Hyper-V host is added to the sources in VMan. That is not an option since i do not wish to monitor the Hyper-V host with Virtualization Manager and i shouldn't be forced to do so. What if i didn't have enough licenses to add the Hyper-V host to Virtualization Manager?
I tried Synchronizing manually (Advanced), to add only the virtual center and not the Hyper-V host but that didn't work out either since the vcenter is already added and the Hyper-V host is not showing/present.