The type or namespace name could not be found [dup

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• Getting “type or namespace name could not be found” but everything seems ok? 30 answers

I have a C# solution with several projects in Visual Studio 2010. One is a test project (I'll call it "PrjTest"), the other is a Windows Forms Application project (I'll call it "PrjForm"). There is also a third project referenced by PrjForm, which it is able to reference and use successfully.

PrjForm references PrjTest, and PrjForm has a class with a using statement:

using PrjTest;

1. Reference has been correctly added
2. using statement is correctly in place
3. Spelling is correct
4. PrjTest builds successfully
5. PrjForm almost builds, but breaks on the using PrjTest; line with the error:

The type or namespace name 'PrjTest' could not be found (are you missing a using directive or an assembly reference?)

I've tried the following to resolve this:

1. Removed Resharper (since Resharper had no trouble recognizing the referenced project, I thought it might be worth a shot)
2. Removed and re-added the reference and using statement
3. Recreated PrjForm from scratch
4. PrjForm currently resides inside the PrjTest folder, I tried moving it to an outside folder
5. Loaded the solution on a different computer with a fresh copy of VS 2010

I have done my homework and spent far too long looking for an answer online, none of the solutions has helped yet.

What else could I try?

Answer 1

check your Project Properties, your Reference Paths should be empty like this:

Regards

Answer 2

I had the same issue. The target frameworks were fine for me. Still it was not working. I installed VS2010 sp1, and did a "Rebuild" on the PrjTest. Then it started working for me.

Answer 3

just changed Application's target framework to ".Net Framework 4".

And error got Disappeared.

good luck; :D

Answer 4

If your project (PrjTest) does not expose any public types within the PrjTest namespace, it will cause that error.

Does the project (PrjTest) include any classes or types in the "PrjTest" namespace which are public?

Answer 5

It is also possible, that the referenced projects targets .NET 4.0, while the Console App Project targets .NET 4.0 Client Library.

While it might not have been related to this particular case, I think someone else can find this information useful.

Answer 6

PrjForm was set to ".Net Framework 4 Client Profile" I changed it to ".Net Framework 4", and now I have a successful build.

This worked for me too. Thanks a lot. I was trying an RDF example for dotNet where in I downloaded kit from dotnetrdf.

NET4 Client Profile: Always target NET4 Client Profile for all your client desktop applications (including Windows Forms and WPF apps).

NET4 Full framework: Target NET4 Full only if the features or assemblies that your app need are not included in the Client Profile. This includes: If you are building Server apps, Such as:

• ASP.Net apps
• Server-side ASMX based web services

If you use legacy client scenarios, Such as: o Use System.Data.OracleClient.dll which is deprecated in NET4 and not included in the Client Profile.

• Use legacy Windows Workflow Foundation 3.0 or 3.5 (WF3.0 , WF3.5)

If you targeting developer scenarios and need tool such as MSBuild or need access to design assemblies such as System.Design.dll