When I started using the Client Object model (Client OM) in SharePoint 2010, I have got this simple error and I just want to share with you in this blog. Following was my develpment environment.

• Windows 7, 64 bit
• Console Application Visual Studio 2010
• Added Client Object Model references (Microsoft.SharePoint.Client.dll & Microsoft.SharePoint.Client.Runtime.dll) to the solution

After setting up all the above, I was trying to add the client reference to the code ‘using Microsoft.SharePoint.Client;‘and then I have got the following error and warnings 🙂

The text format of error is:

"The type or namespace name 'SharePoint' does not exist in the namespace 'Microsoft' (are you missing an assembly reference?)"

It’s an obvious error message and the reason of this error is:

SharePoint 2010 does not support .Net 4.0 in default and Visual Studio 2010 default framework is .Net 4.0.

Here are the simple steps to fix this:

Step 1: Right click on the project –> Properties

Step 2: Change the Target framework –> .Net Framework 3.5

Step 3: Warning message will be popping up, click Yes.

That’s all. Happy Coding..!

Please Note: If you use Windows Application then you will be getting an other error message! 😦 To solve this issue just click here.