Thanks for the fast reply!
However...
I realize these are microsoft issues at the core.
But each of the two solutions given in the answer give a new issue.
After installing MVC4 globally I now get:
Error CS1705 Assembly 'DayPilot.Web.Mvc' with identity 'DayPilot.Web.Mvc, Version=2020.1.6007.0, Culture=neutral, PublicKeyToken=b8d928e6588028e4' uses 'System.Web.Mvc, Version=4.0.0.1, Culture=neutral, PublicKeyToken=31bf3856ad364e35' which has a higher version than referenced assembly 'System.Web.Mvc' with identity 'System.Web.Mvc, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' Demo....
and the MVC5 version gives the following error:
.. well it looks like I can't copy the nuGet error text.
It basically says an error occurred while trying to restore packages: unable to find Version 3.2.2 of package Microsoft.AspNet.WebPages.
Nuget cannot uninstall it as it seems to try to restore it first and just errors. I cannot update to a higher version either.
If I run the application I get a yellow screen of death stating:
Could not load file or assembly 'System.Web.Helpers' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
I really didn't think I was that inept at working these things out but it appears I am...
I really wanted the javascript version as I found that and got it up and running fairly quickly and was impressed. However I discovered I needed Pro to do what I needed. But it seems bait and switch. It is not javascript. It is either Angular or React for Pro. I really do not want to install those frameworks and deal with unknown (to me) syntax/Technology...
Thanks for any help...