I'm trying to just build a super simple web part for on-prem, I go into VS 2017 and I select SharePoint 2016 - Visual Web Part, I don't modify any of the code and then I just compile and deploy and attempt to test.
However, I get this error when I try to add it to a page:
I've done some googling, not really sure what the solution is here, most of the resources on the web seem inconsistent.
Any ideas of what needs to be done? I've seen some references to "SafeControls" needing to be added but again, info is inconsistent about this.