SharePoint 2013 BCS with WCF data source: Unknown Error occurred. Unable to load one or more of the requested types.

This is a common error that you would have faced, while adding a WCF service endpoint to BCS through SharePoint Designer 2013, connected to Office 365. The complete error would look like this:

Unknown Error occurred. Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.

This is an error observed while connecting to a WCF data source through SharePoint Design 2013. Ensure that your WCF service endpoint is working perfectly.


STEP 1: Open the “SPDESIGN.exe.config” file from SharePoint Designer folder ()

STEP 2: Update the file with the following configuration:

<?xml version=”1.0″ ?>
<requiredRuntime version=”v2.0.50727″ />
<supportedRuntime version=”v2.0.50727″ />
<assemblyBinding xmlns=”urn:schemas-microsoft-com:asm.v1″>
<assemblyIdentity name=”Microsoft.BusinessData” publicKeyToken=”71e9bce111e9429c” culture=”neutral” />
<bindingRedirect oldVersion=”″ newVersion=”″/>

STEP 3: Save the file and run SharePoint Designer once again.

STEP 4: Try adding your WCF data source once again. Voila! you should see it work now…:)

The fix is just telling SPD to run BCS on version, if its gets a reference to version I guess our Office 365 online considers SharePoint 2013 version as 16, instead of 15. Forward thinking…quite understandable…:)

Hope this helps!



  1. I was running the 32 bit version of SPD and inserting the runtime section (recommended above) did not change the error. I tried removing the new runtime section and had the same result as Andrew (broken SPD). I uninstalled SPD and reinstalled but this time the 64bit (not sure what difference that makes but previously I had office 2013 installed as 32 bit so SPD was installed 32 bit to match the office install). I tried adding the runtime section with the 64bit and no change (same error). I am wondering if by chance the runtime version has been updated since the time of this blog or if there are any other adjustments needed to make this solution work. I was so hopeful that this was going to mean the SUCCESSFUL conclusion of a very long journey.


  2. Worked for me, thanks!

    Make sure you don’t simply copy-paste from this page. The quotes aren’t valid.


  3. When I change to same as this. I got an error: “The Business Connectivity Metadata Store is currently unavailable”.
    This error was happened when I use the version ‘click to run’ from Office 365 portal. so I have to download and installed the standalone version to resolved this issues.

    my config file is:

    Do you have any suggestion?



  4. Broke my spd


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