What helped for me was reducing the number of server discovery threads from 8 to 1 in the vscPreferences.xml file.
I stopped the Virtual Storage Console service and edited the vscPreferences.xml file in "C:\Program Files\NetApp\Virtual Storage Console\etc\vsc\", and changed the folowing line:
<entry key="default.server.discovery.threads" value="1"/>
Next, I started the VSC service again and the queued discovery tasks were removed and ran succesfully ever since.