Unable to remove unused tags remaining from old shared notebooks

[Mirra 2]

Hi guys,

 

I am using Evernote since a few years, and have thousands of notes in it. Today I decided to remove some of the shared notebooks (shared with me by 3rd persons), because they were not anymore relevant. However, now I am stuck with a huge bunch of unused tags that these notebooks contained, and the problem is that I cannot remove them! When I right-click on these tags with my mouse, the option "delete" is not even highlighted, the only thing it allows me to do is add the tag to the shortcuts. 

 

Is there any solution to it?

 

I'm using Evernote for Windows, v 5.6. (premium account)

 

Thanks for your help in advance!

Mirra