The extensible extension returned an unsupported error.
 The stack trace is:

 "System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> System.IO.FileLoadException: Could not load file or assembly 'System.Net.Http.Extensions, Version=1.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
   at Simple.OData.Client.HttpConnection.CreateMessageHandler(ODataClientSettings settings)
   at Simple.OData.Client.HttpConnection..ctor(ODataClientSettings settings)
   at Simple.OData.Client.Session.GetHttpConnection()
   at Simple.OData.Client.RequestRunner.<ExecuteRequestAsync>d__2.MoveNext()

Assembly manager loaded from:  C:\Windows\Microsoft.NET\Framework64\v4.0.30319\clr.dll
Running under executable  C:\Program Files\Microsoft Forefront Identity Manager\2010\Synchronization Service\Bin\miiserver.exe
--- A detailed error log follows.

=== Pre-bind state information ===
LOG: DisplayName = System.Net.Http.Extensions, Version=1.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
 (Fully-specified)
LOG: Appbase = file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/
LOG: Initial PrivatePath = NULL
Calling assembly : Simple.OData.Client.Core, Version=4.28.0.0, Culture=neutral, PublicKeyToken=null.
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:\Program Files\Microsoft Forefront Identity Manager\2010\Synchronization Service\Bin\miiserver.exe.Config
LOG: Using host configuration file:
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework64\v4.0.30319\config\machine.config.
LOG: Post-policy reference: System.Net.Http.Extensions, Version=1.5.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/System.Net.Http.Extensions.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/System.Net.Http.Extensions/System.Net.Http.Extensions.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/bin/System.Net.Http.Extensions.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/bin/System.Net.Http.Extensions/System.Net.Http.Extensions.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/bin/assemblies/System.Net.Http.Extensions.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/bin/assemblies/System.Net.Http.Extensions/System.Net.Http.Extensions.DLL.
LOG: Attempting download of new URL file:///C:/Program Files/Microsoft Forefront Identity Manager/2010/Synchronization Service/Extensions/System.Net.Http.Extensions.DLL.
WRN: Comparing the assembly name resulted in the mismatch: Major Version
ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.
<---
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Forefront Identity Manager 4.4.1237.0"