Kentico 11+ WebForms PortalEngine and WebObjectActivator

Has anyone had any success with setting a DI adapter to HttpRuntime.WebObjectActivator on a Kentico 11 hotfix 24 WebForms PortalEngine website?

With https://www.nuget.org/packages/DependencyInjection.WebForms.Unity/ being added on Global.asax Application_Start any page/admin request is producing the following error for me:

[Exception: Only one page manager (CMSPageManager or CMSPortalManager) is allowed on the page.]
   CMS.PortalEngine.PortalContext.set_CurrentPageManager(IPageManager value) +90
   CMS.PortalEngine.Web.UI.CMSPortalManager..ctor() +210

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) +0
   System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +328
   Unity.Processors.<>c__DisplayClass16_0.<GetResolverDelegate>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Constructor\ConstructorResolution.cs:79
   Unity.Processors.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Abstracts\MemberProcessor.cs:162
   Unity.Processors.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Abstracts\MemberProcessor.cs:162
   Unity.Processors.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Abstracts\MemberProcessor.cs:162
   Unity.<>c__DisplayClass111_0.<OptimizingFactory>b__0(BuilderContext& c) in C:\projects\unity\Container\src\UnityContainer.Resolution.cs:271
   Unity.Strategies.BuildPlanStrategy.PreBuildUp(BuilderContext& context) in C:\projects\unity\Container\src\Strategies\BuildPlanStrategy.cs:88
   Unity.<>c.<.ctor>b__73_2(BuilderStrategy[] chain, BuilderContext& context) in C:\projects\unity\Container\src\UnityContainer.Resolution.cs:420
   Unity.Builder.BuilderContext.Resolve(Type type, String name, InternalRegistration registration) in C:\projects\unity\Container\src\Builder\Context\BuilderContext.cs:177
   Unity.Builder.BuilderContext.Resolve(Type type, String name) in C:\projects\unity\Container\src\Builder\Context\BuilderContext.cs:44
   Unity.Builder.BuilderContext.Resolve(ParameterInfo parameter, Object value) in C:\projects\unity\Container\src\Builder\Context\BuilderContext.cs:217
   Unity.Processors.<>c__DisplayClass7_0.<CreateParameterResolvers>b__0(BuilderContext& context) in C:\projects\unity\Container\src\Processors\Parameters\ParametersProcessor.cs:121
   Unity.Processors.<>c__DisplayClass16_0.<GetResolverDelegate>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Constructor\ConstructorResolution.cs:77
   Unity.Processors.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Abstracts\MemberProcessor.cs:162
   Unity.Processors.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Abstracts\MemberProcessor.cs:162
   Unity.Processors.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c) in C:\projects\unity\Container\src\Processors\Abstracts\MemberProcessor.cs:162
   Unity.<>c__DisplayClass111_0.<OptimizingFactory>b__0(BuilderContext& c) in C:\projects\unity\Container\src\UnityContainer.Resolution.cs:271
   Unity.Strategies.BuildPlanStrategy.PreBuildUp(BuilderContext& context) in C:\projects\unity\Container\src\Strategies\BuildPlanStrategy.cs:80
   Unity.<>c.<.ctor>b__73_1(BuilderContext& context) in C:\projects\unity\Container\src\UnityContainer.Resolution.cs:361
   Unity.UnityContainer.Unity.IUnityContainer.Resolve(Type type, String name, ResolverOverride[] overrides) in C:\projects\unity\Container\src\UnityContainer.IUnityContainer.cs:244
   Unity.UnityContainerExtensions.Resolve(IUnityContainer container, Type t, ResolverOverride[] overrides) in C:\projects\unity\Abstractions\src\Extensions\Container\UnityContainer.cs:913
   HouseofCat.DependencyInjection.WebForms.Unity.ContainerServiceProvider.GetService(Type serviceType) in C:\GitHub\personal\HouseofCat.DependencyInjection.WebForms.Unity\ContainerServiceProvider.cs:49
   ASP.cmspages_portaltemplate_aspx.__BuildControlplcRoot() in C:\GIT\tests\KenticoTests\CMS\CMSPages\PortalTemplate.aspx:0
   ASP.cmspages_portaltemplate_aspx.__BuildControlform() in C:\GIT\tests\KenticoTests\CMS\CMSPages\PortalTemplate.aspx:13
   ASP.cmspages_portaltemplate_aspx.__BuildControlTree(cmspages_portaltemplate_aspx __ctrl) in C:\GIT\tests\KenticoTests\CMS\CMSPages\PortalTemplate.aspx:1
   ASP.cmspages_portaltemplate_aspx.FrameworkInitialize() +54
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +48
   System.Web.UI.Page.ProcessRequest() +76
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +24
   System.Web.UI.Page.ProcessRequest(HttpContext context) +62
   ASP.cmspages_portaltemplate_aspx.ProcessRequest(HttpContext context) +48
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +195
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +50
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +73

If I don't add the adapter I get no error, I can't really tell why the PortalContext.CurrentPageManager is already initialized for it to throw that error when the page/controls are being built up.

Any help getting to the bottom of it would be greatly appreciated.

Update 1

Application_Start is just using this extension method: https://github.com/houseofcat/DependencyInjection.WebForms/blob/5bf89863f083eb4d0aebb65f0c3a9e06cfd633b5/src/DependencyInjection.WebForms.Unity/HttpApplicationExtensions.cs#L19 to add the container.

I haven't added any registrations yet, only the IUnityContainer is registered in the container.

Solution

If you're looking to use DI with HttpRuntime.WebObjectActivator on Kentico, you'll need Kentico 12+.