I downloaded a demo which had the dll in it.I believe that I was using the demo before I downloaded the trial. And I downloaded other demos subsequently. When I went into the project I saw it was pointing to a 2014 version, so I found a later version in another demo (C:\Users\Larry\Downloads\ui-for-aspnet-mvc-examples\ui-for-aspnet-mvc-examples-master\window\KendoWindow-Ajax-Form\lib\KENDOUIMVC\2016.3.914.545) and used that and since have not been having this issue. Using this version did solve the license error and the excel error (though I'm still working to get that working).
I've added the js reference below.
Note that my libraries from the demo show 2015 - can I safely update them to a more recent version?
<link href="https://kendo.cdn.telerik.com/2015.3.1111/styles/kendo.dataviz.min.css" rel="stylesheet">
<link href="https://kendo.cdn.telerik.com/2015.3.1111/styles/kendo.dataviz.metro.min.css" rel="stylesheet">
Note that there is no kendo.mvc.dll in C:\Users\Larry\Downloads\telerik.kendoui.professional.2017.1.223.trial.
I'll downloading the trial again. Originally I downloaded the whole dev suite.
When I try to use the library in C:\Program Files (x86)\Telerik\UI for ASP.NET MVC R1 2017\wrappers\aspnetmvc\Binaries\Mvc4 or MVC5 - I don't get an error of any sort but no data is returned. To get data, so far I have to use C:\Users\Larry\Downloads\ui-for-aspnet-mvc-examples\ui-for-aspnet-mvc-examples-master\window\KendoWindow-Ajax-Form\lib\KENDOUIMVC\2016.3.914.545\Kendo.Mvc.dll
When use the kendo.mvc.dll in C:\Users\Larry\Downloads\ContainsByDefaultInFilter\ContainsByDefaultInFilter\ContainsByDefaultInFilter\bin then I do get the license exception for some reason.
[LicenseException: Your trial version of Telerik UI for ASP.NET MVC by Progress has expired. Purchase the commercial version now from www.telerik.com/purchase or extend your trial with 15 more days by contacting firstname.lastname@example.org]
Kendo.Mvc.Infrastructure.Licensing.KendoLicenseProvider.Validate(Type type, Object instance) +303