VMware vCenter Server not scanned in 11.1.1.3

[WuGe]

Since the update to v11.1.1.3 my VMware vCenter Server is not scanned anylonger.
It also no longer shows up as an asset.

Before the update all was OK. The vCenter and all scanned information was there.
We upgraded from v10.6.2.0
Scanning credentials are OK.
I have the vCenter IP with credentials as scanning target to scan it manually.
I can trigger the scan manually, the IP shows up in the scanning queue but seems not to be scanned because the vCenter server does not show up as asset and the widget stays empty.

Any ideas?

Update:
Logon with the given credentials works on the webclient/webpage of the vcenter.
LS calls the api and that logon runs into the error.

[AlbertD222]

Sorry just seeing this. Looks like you opened a ticket, but still wanted to answer your question...

Our Scan Server freezes I guess is the best way to put it. The Service is "Running" on the server, but in Lansweeper it says its stopped. If I stop the service in Windows it eventually times out with an error, and then lets me start the service back up. Which then works for a while until I either scan an item based on its IP or Linux based item (not sure which causes the problem, yet). If i turn all scanning off, and only leave Active Directory scanning on, it works fine. 

[WuGe]

@AlbertD222 What I can see that is not an issue on my installation.