If you're not able to click on a land ownership parcel it most probably means the land is not registered at the Land Registry.
Here is an example of what happens of when you try to click on unregistered land in the Ownership Layer. The land in the middle is unregistered.
In the above example the land in the middle is unregistered.
Over 85% of land and property in England and Wales is now registered with Land Registry. Much of the land owned by the Crown, the aristocracy, and the Church has not been registered, because it has never been sold, which is one of the main triggers for compulsory registration. For more information on how to find the owner of unregistered land, read the article Registered or unregistered land, that is the question.
If you are looking for unregistered land in general, you can use it as a search filter in the Property Information layer. This is not an exhaustive search of all unregistered land, however it can be very useful.
If you are certain that the land ownership parcel you can’t seem to click on is registered, get in touch.