This happen after you disable via Control Panel -> network adapters -> right click button on the virtual connection -> disable
To fix that go to Device Manager (Windows-key + x + m on windows 8, Windows-key + x then m on windows 10), then open the network adapters tree , right click button on Microsoft Hosted Network Virtual Adapter and click on enable.
Try now with the command netsh wlan start hostednetwork with admin privileges. It should work.
Note: If you don’t see the network adapter with name ‘Microsoft Hosted Network Virtual Adapter’ try on menu -> view -> show hidden devices in the Device Manager window.
Let alone enabling the network adapter under Device Manager may not help. The following helped me resolved the issue.
I tried Disabling and Enabling the Wifi Adapter (i.e. the actual Wifi device adapter not the virtual adapters) in Control Panel -> Network and Internet -> Network Connections altogether worked for me. The same can be done from the Device Manager too. This surely resets the adapter settings and for the Wifi Adapter and the Virtual Miniport adapters.
However, please make sure that the mode is set to allow as in the below example before you run the start command.
netsh wlan set hostednetwork mode=allow ssid=ssidOfUrChoice key=keyOfUrChoice
and after that run the command netsh wlan start hostednetwork.
Also once the usage is over with the Miniport adapter connection, it is a good practice to stop it using the following command.
netsh wlan stop hostednetwork
Hope it helps.