If you are still using the VMWare vSphere Client, and are unable to search the inventory, you are most likely recieving the following error:
Login to the query service failed.The server could not interpret the communication from the client. (The remote server returned an error: (500) Internal Server Error.)
If this is the case, aparently this should be an expected behaviour, provided you have logged into the Client and used the Use Windows Credentials option.
To restore the search functionality, make sure that when you are logging in, you manually enter your login credentials.
To my surprise, after testing this, i have found a 3 year old article from VMWare – https://kb.vmware.com/s/article/2143566 🙂