2020: Year of the Illumination?

Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.CompilationFailedException: One or more compilation failures occurred:
1etx5y1l.wmz(18,77): error CS0234: The type or namespace name 'Web' does not exist in the namespace 'Umbraco' (are you missing an assembly reference?)
1etx5y1l.wmz(23,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(33,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(41,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(49,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(57,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(65,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(77,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(85,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(93,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(101,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
1etx5y1l.wmz(109,13): error CS0103: The name 'WriteLiteral' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(3,6): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,11): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,12): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,48): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,49): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,73): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,74): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,92): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(6,99): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,11): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,12): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,42): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,43): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,61): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,62): error CS0103: The name 'Model' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,75): error CS0103: The name 'Write' does not exist in the current context
C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\App_Plugins\HtagGridEditor\views\headline.render.cshtml(12,82): error CS0103: The name 'Model' does not exist in the current context
   at Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.RuntimeViewCompiler.CompileAndEmit(RazorCodeDocument codeDocument, String generatedCode)
   at Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.RuntimeViewCompiler.CompileAndEmit(String relativePath)
   at Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.RuntimeViewCompiler.OnCacheMiss(String normalizedPath)
--- End of stack trace from previous location ---
   at Microsoft.AspNetCore.Mvc.Razor.RazorViewEngine.CreateCacheResult(HashSet`1 expirationTokens, String relativePath, Boolean isMainPage)
   at Microsoft.AspNetCore.Mvc.Razor.RazorViewEngine.LocatePageFromPath(String executingFilePath, String pagePath, Boolean isMainPage)
   at Umbraco.Cms.Web.Website.ViewEngines.ProfilingViewEngine.GetView(String executingFilePath, String viewPath, Boolean isMainPage)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper.RenderPartialCoreAsync(String partialViewName, Object model, ViewDataDictionary viewData, TextWriter writer)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper.PartialAsync(String partialViewName, Object model, ViewDataDictionary viewData)
   at AspNetCore.Views_Partials_grid_editors_base.ExecuteAsync() in C:\inetpub\vhosts\afterthewarning.com\Atw13\live.AtW-U13\Views\Partials\grid\editors\base.cshtml:line 6