Nodes -- Unable to select Nodes under Library tab

Currently following Ian Seigel’s Dynamo 2.x Essential Training on LinkedIn Learning and I’m unable to select a Node, any Node from the Library.

I am in a new Dynamo file. Using Revit 2021. Dynamo Core 2.6.1.8786. Dynamo Revit 2.6.1.8850.
Screenshot 2020-10-05 154149

Any ideas? Do I need to reinstall Dynamo? (How would I do that???) Or is their a newer more stable version than what installed with Revit 2021?

Thanks in advance!