Type or Namespace could not be found. But references are there

Question

Currently I am using 2 references in my C# project:

using Czm.Perimetry.Analysis.Core;
using Czm.Perimetry.Analysis.IO;

And when I look at my project in Visual Studio no errors come up. However when I run the project I get:

Error   CS0246  The type or namespace name 'Czm' could not be found
(are you missing a using directive or an assembly reference?)       

I don't understand what's going on, and nothing else with the project comes up with an error.

Hulda

Answer 1

Check if the assemblies referenced (Czm) are running against the same framework your project is.

If not, VS might false-positive the reference, while being unable to load the assemblies correctly in runtime.

Disturbed

Answer 2

In my case just now, these errors showed up for no discernable reason while refactoring and moving around namespaces in a library being referenced by another library in the project. The fix was to unload and reload the library projects.

Nickelsen

You're my hero, I wish I could upvote this more. – Slump

Answer 3

If you have the same project referenced in more than one other project or solution, double-check those. I had to remove and re-add the project reference after I recreated the referenced project from another solution and I supposed the GUID changed.

Spoliation

Answer 4

I updated some references to a new Version of a software's SDK. they needed a higher version of .net than I was using. But I did not get an error about the version of .net. I just got a "could not find reference" like listed in OP. I had to update the project's .net version to match the assemblies referenced and it fixed the problem.

Harveyharvie

Answer 5

It was because of dependencies in the solution not getting linked properly in my case. Below steps resolved my issue:

1. Go to dependencies in the project
2. right click on the project then select add project reference.
3. select the required project references.
4. Rebuild the solution

Khiva

Answer 6

For me it was the fact that I accidentally changed the version of the framework I was working under, which was different from when I created the classes that could no longer be referenced. When I changed the target framework to match, everything was fine.

Bonacci