If you use WMware ESXi product to manage all your virtual resources. you may met this issue.
The scenario like below:
Some bad things happened on your host, and esx.conf file maybe corrupted at that time. You can see some Virtual Switch have no associate VM attached, it means this is an orphan virtual switch. you can not remove it directly since it's in lock state.
Solution:
1. login to ESX host
2. restart services "services.sh restart"
3. wait the process finish and reconnect your host to Vcenter.
4. remove your orphan VS from your host.
That's all! at least resolve my case! LOL.