The type or namespace name could not be found [duplicate]
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The type or namespace name could not be found [duplicate]
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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.
C#
Visual Studio 2010
Windows Forms Application
PrjForm references PrjTest, and PrjForm has a class with a using statement:
using
using PrjTest;
using
using PrjTest;
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:
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?
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
Wouldn't you know it: stackoverflow.com/questions/4286599/… Turns out this was a client profiling issue, I didn't even think to check for that..
– Anders
Jan 21 '11 at 23:45
@Shekhar_Pro: I'm sure, it was one of the first things I checked..
– Anders
Jan 21 '11 at 23:46
Yep... this is generally a
.NET Framework incompatibilitymismatch thingy. The problem is that Visual Studio (even 2013) won't tell you that in the Error List output window. :(– Leniel Maccaferri
Jul 1 '14 at 15:15
.NET Framework
Error List
I've closed this as a duplicate because after careful reading your issue was the exact same one as the duplicate which pre-dates this question by 6 months. (Your issue was a client profile assembly referencing a full framework assembly).
– slugster
Jan 23 '15 at 1:05
16 Answers
16
See this question.
Turns out this was a client profiling issue.
PrjForm was set to ".Net Framework 4 Client Profile"
I changed it to ".Net Framework 4", and now I have a successful build.
Thanks everyone!
I guess it figures that after all that time spent searching online, I find the solution minutes after posting, I guess the trick is knowing the right question to ask..
It is actually a shame nor VS nor the C# compiler can provide a useful error description that would have avoid you (and me) this pain!
– Patrick from NDepend team
Jun 20 '12 at 12:16
Same error, but in my case I was trying to use a 4.0 dll in a 3.5 project.
– Mikey G
Apr 9 '13 at 20:32
Same error, but here it was 4.5 dll in 4.0 project.
– CW30Meters
Nov 26 '13 at 14:15
This happened to me last week but from loading a 4.5.2 library in a 4.5 project. Just a note: A 4.5.2 project can load a 4.5 or 4.5.1 library just fine.
– ahwm
Jan 12 '15 at 16:13
Thank you! scratching my head for an hour! I accidentally added a 4.6.2 proj and not 4.5.2.
– Tez Wingfield
Sep 11 '16 at 13:22
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:
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.
If you targeting developer scenarios and need tool such as MSBuild or need access to design assemblies such as System.Design.dll
In my case, I had 3 projects in 1 solution. I had to set them all to .Net Framework 4.5 and then I could compile! Its annoying that the error message was misleading.
– rf_wilson
Jun 10 '14 at 12:25
In my case I had:
Referenced DLL : .NET 4.5
.NET 4.5
Project : .NET 4.0
.NET 4.0
Because of the above mismatch, the 4.0 project couldn't see inside the namespace of the 4.5 .DLL. I recompiled the .DLL to target .NET 4.0 and I was fine.
damn, i face this exactly after 6 years and it took me 1 hour to find out! thanks!
– zeroflaw
Jan 26 at 7:36
Another thing that can cause this error is having NuGet packages that have been built with a newer version of .NET.
The original error:
frmTestPlanSelector.cs(11,7): error CS0246: The type or namespace name 'DatabaseManager'
could not be found (are you missing a using directive or an assembly reference?)
Further up in the log I found this:
C:WindowsMicrosoft.NETFrameworkv4.0.30319Microsoft.Common.targets(1605,5): warning MSB3275: The primary reference "[redacted]DatabaseManagerbinReleaseDatabaseManager.dll" could not be resolved because it has an indirect dependency on the assembly "System.Data.SQLite, Version=1.0.94.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139" which was built against the ".NETFramework,Version=v4.5" framework. This is a higher version than the currently targeted framework ".NETFramework,Version=v4.0".
C:WindowsMicrosoft.NETFrameworkv4.0.30319Microsoft.Common.targets(1605,5): warning MSB3275: The primary reference "[redacted]DatabaseManagerbinReleaseDatabaseManager.dll" could not be resolved because it has an indirect dependency on the assembly "System.Data.SQLite, Version=1.0.94.0, Culture=neutral, PublicKeyToken=db937bc2d44ff139" which was built against the ".NETFramework,Version=v4.5" framework. This is a higher version than the currently targeted framework ".NETFramework,Version=v4.0".
The solution was to re-install the NuGet packages:
http://docs.nuget.org/docs/workflows/reinstalling-packages
this did it for me, my app was targeting 4.5.2 but unit tests were on 4.5 thanks.
– roo2
Aug 19 '15 at 6:12
This one! I had shut off warnings because, you know, WARN... Turned that back on and it showed the error straight away.
– Mutmatt
Jun 27 at 19:10
I solved mine because the other project was coded with .NET 4.5 and the other one was coded 4.0
I had the same issue between .NET 4.0 and .NET 4.0 Client Profile. Good call.
– Andrew Grothe
Sep 10 '13 at 13:50
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.
I encountered this issue it turned out to be.
Project B references Project A.
Project A compiled as A.dll (assembly name = A).
Project B compiled as A.dll (assembly name A).
Visual Studio 2010 wasn't catching this. Resharper was okay, but wouldn't compile. WinForms designer gave misleading error message saying likely resulting from incompatbile platform targets.
The solution, after a painful day, was to make sure assemblies don't have same name.
The using statement refers to a namespace, not a project.
Make sure that you have the appropriately named namespace in your referenced project:
namespace PrjTest
public class Foo
// etc...
Read more about namespaces on MSDN:
Thanks Mark, I do have the namespace appropriately named.
– Anders
Jan 21 '11 at 23:53
Had the same issue, Thank You!
– Jamey McElveen
May 25 '12 at 13:14
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.
The compiled dll should have public Class.
Changing the framework to
did the job for me.
You bring up a good point: as long as all your projects are using the same framework, it should fix the issue - whether it's the client profile or an earlier version of .Net.
– Anders
Oct 1 '12 at 14:33
For COM/ActiveX references, VS 2012 will show this error right on using statement. Which is quite funny, since it's saying that may be you are missing a using statement.
To solve this: register the actual COM/ActiveX dll even if it's in the neighbor project, and add a reference through COM channel, not project channel. It will add Interop.ProjectName instead of ProjectName as a reference and this solves this strange bug.
If your project (PrjTest) does not expose any public types within the PrjTest namespace, it will cause that error.
PrjTest
Does the project (PrjTest) include any classes or types in the "PrjTest" namespace which are public?
Thanks for the insight, I'm learning a lot about this. PrjTest includes around 50 public classes; it's a decent-sized project
– Anders
Jan 23 '11 at 17:40
just changed Application's target framework to ".Net Framework 4".
And error got Disappeared.
good luck;
:D
How to change the applications target name please?
– A user
Dec 8 '16 at 15:34
Other problem that might be causing such behavior are build configurations.
I had two projects with configurations set to be built to specific folders.
Like Debug and Any CPU and in second it was Debug and x86.
Debug
Any CPU
Debug
x86
What I did I went to Solution->Context menu->Properties->Configuration properties->Configuration and I set all my projects to use same configurations Debug and x86 and also checked Build tick mark.
Solution->Context menu->Properties->Configuration properties->Configuration
Debug
x86
Build
Then projects started to build correctly and were able to see namespaces.
check your Project Properties, your Reference Paths should be empty like this:
Regards
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are you sure the PrjTest has a Namespace named PrjTest
– Shekhar_Pro
Jan 21 '11 at 23:41