Adapter edit UI displays 'System.MissingMethodException: Method not found: 'Void Unify.Connect.Web.Client.AdapterClient..ctor(System.String)'' error in Broker 5.3.1.4

When I attempt to access an Adapter in the web UI in Broker 5.3.1.4 the following error screen appears.  This happens for all existing Adapters, and as the last step when creating a new Adapter (which is written to the Extensibility config file just fine).  The Agents, Connectors and other UI screens work just fine.  I am using IIS on the same server as the Broker Service is installed, and Plus and a number of other agents are also installed (see below for details).  The Extensibility files are based on a fresh install of all Broker packages.

The text is:

Error

System.MissingMethodException: Method not found: 'Void Unify.Connect.Web.Client.AdapterClient..ctor(System.String)'.
at Unify.Connect.Web.PlusControllerBase.get_AdapterClient()
at Unify.Connect.Web.LockerControllerFactory.<CreateComponent>b__0_0(HtmlHelper html, AdapterDetailsProviderInformation info)
at Unify.Connect.Web.AdapterDetailsProvider.WriteAll(HtmlHelper helper, AdapterDetailsProviderInformation adapterDetails)
at ASP._Page_Views_Adapter_AdapterDetails_cshtml.Execute() in c:\Program Files\UNIFY Solutions\Identity Broker\Web\Views\Adapter\AdapterDetails.cshtml:line 152
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
at System.Web.WebPages.StartPage.ExecutePageHierarchy()
at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass1e.<BeginInvokeAction>b__1b(IAsyncResult asyncResult)

The error refers to line 152 of c:\Program Files\UNIFY Solutions\Identity Broker\Web\Views\Adapter\AdapterDetails.cshtml which reads as follows:

AdapterDetailsProvider.Instance.WriteAll(Html, adapterDetailsProviderInformation);

Here are details of the install:

UNIFYBroker

Plug-in Version Details

Here is a snapshot of the folder containing the file reported in the error:

Here are the Adapter Extensibility file entries that were created successfully:

Please let me know if there is any more information that you require.