Hey Wayne - welcome to our community!
Feel free to Introduce yourself 
if you’d like 
Looking at your Revit toolbar, that is most likely due to a conflict with another installed plugin 
and unfortunately there is very little we can do to help in these situations.
What I can suggest is to deactivate the other plugins until you pinpoint the conflicting one. To do so you can simply rename the other plugin manifests from samplerevitplugin.addin to samplerevitplugin.addin_disabled.
These are the directories to look at:
%appdata%\Autodesk\Revit\Addins\
%appdata%\Autodesk\ApplicationPlugins\
C:\ProgramData\Autodesk\Revit\Addins\
C:\ProgramData\Autodesk\ApplicationPlugins\
C:\Program Files\Autodesk\Revit 20XX\AddIns\
To narrow your search even more, try finding the plugins that have a Revit.Async.dll file in their folder.
Let me know how it goes!