I.T performed a registry clean after they deleted ALL dynamo files.
They also deleted the core files that are automatically included with the newer versions of Revit.
Here is a link to the free download of the registry cleaner I.T used on my machine.
This worked for me.
The last item they carried out was updating my revit firmware. Revit 2018,2 to revit 2018.3. I’m aware you’re using 2017 however upgrading the version might work also. (Check other users are compatible in your office first)