.NET Framework support in SharePoint 2010

There are recent customer questions about .NET Framework support in SharePoint. For example, there is this question in the SharePoint 2010 forums, as well as several customer questions at SharePoint booth at TechEd.

SharePoint 2010 does not support access from .NET Framework 4 or being run in a .NET Framework 4 app domain. If you must support the .NET Framework 4, we recommend that you develop a web service that uses the .NET Framework 4 and then connect to it from SharePoint. All server-side customizations directly for SharePoint 2010 still need to be either the .NET Framework 3.5 or the .NET Framework 3.5 SP1.

For more information, see the following MSDN Library topics.


However, you can use Silverlight 4 and Silverlight 5 against the SharePoint client object model. For more information, see the following MSDN Library topics.

Comments (7)

  1. Héctor says:


    How are you?

    I would like to know if it's recommended/supported or not to install .net framework 4.0 on a SPS 2010 production environment. I didn't find any information regarding to that.


    Kind Regards.

  2. Hi Héctor,

    Yes, installing .NET Framework 4 on the same computer as SharePoint 2010 is supported. For example, if you install Visual Studio 2010 on a computer with SharePoint 2010 for development purposes, the .NET Framework 4 would co-exist with SharePoint 2010.

  3. Tim says:


    Could you please explain a bit more how I connect a web service from SP 2010?

  4. .Net with Sharepoint Developer -NC says:

    Contact me on-  [ arjun.s@bluebirdtechnologies.com ]

    Job Title: .NET with SharePoint

    Location: Raleigh, NC

    Duration: 6+ Months

    Must to have: .NET 3.5/4.0, C#, SharePoint 2007 & 2010, SQL Server

    Required Skills:

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    • Experience developing advanced custom SharePoint 2007 and 2010 webparts

    • Knowledge of relational database development concepts

    • Building Public Corporate websites and collaboration solutions using MS SharePoint 2010

    • Experience with designing and deploying Public facing websites – Internet, Extranet and Intranet sites

    • Experience with SharePoint 2010 content management and publishing

    • Experience with HTML5, CSS and JavaScript

    • Knowledge of Microsoft Access databases and VBA language

    • Knowledge of Microsoft SQL Server Report Server 2008 (SR)

    • Knowledge of Enterprise Messaging and Data Orchestration

    • Understanding of Microsoft Dynamics CRM 4.0 and CRM 2011

    • Understanding of SCRIBE Insight is a plus

    • Meets project deadlines and likes working in a fast paced environment

    • Communicate with both technical and non-technical staff to support analysis, design, testing, and troubleshooting of project issues as related to usability and design

    • Must have strong attention to detail and be able to work as a team player

    • A college graduate possessing 1-3 years of work experience

    • Outstanding interpersonal skills, including the ability to work effectively in a team environment, handle internal clients with tact and diplomacy, and maintain composure and production quality under deadline pressure

    • Excellent writing, editing and proofing skills

  5. ITM says:

    We have a .NET web application developed using .NET 4.0. Our application was able to connect to earlier versions of SharePoint using the API, but has failed with SharePoint 2010 due to this restriction. We are unable to create a web services to connect to our app from SP – it is not feasible.

    Why would Microsoft implement such a restriction in SP 2010? Our application's feature has effectively been broken.  What workarounds or fixes do you have?

  6. Jason says:

    We see the error

    Exception information:

       Exception type: ConfigurationErrorsException

       Exception message: Could not find permission set named 'ASP.Net'.

      at System.Web.Hosting.ApplicationManager.CreateAppDomainWithHostingEnvironment(String appId, IApplicationHost appHost, HostingEnvironmentParameters hostingParameters)   at System.Web.HttpRuntime.HostingInit(HostingEnvironmentFlags hostingFlags, PolicyLevel policyLevel, Exception appDomainCreationException)

  7. Jason says:

    SharePoint 2013 supports .Net 4.0 though right? That is the default on the application pools for SharePoint such as "Sharepoint Central Administration v4" as I see in in the list of Application Pools in IIS Manager.

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