Error CS0234: The type or namespace name ‘HelloWorld.Core’ does not exist in the namespace ‘HelloWorld’

Warning MSB3245: Could not resolve this reference. Could not locate the assembly “HelloWorld.Core”. Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.

Error CS0234: The type or namespace name ‘Core’ does not exist in the namespace ‘Document360’ (are you missing an assembly reference?)

Are you seeing your Azure Pipelines build failing with similar error/warning message? It’s very likely that it’s a missing project dependency issue. It’s a usual case when you have a solution inside which you have multiple project and have added project-A as a dependency in project-B under the same solution.

How to fix Error CS0234: The type or namespace name ‘XXXX.Core’ does not exist in the namespace ‘XXXX’?

Check if you have added the project as dependency. It’s likely that you may have added the reference to the project’s DLL instead of the Project itself inside the solution.

While adding the reference to another project – always add the reference to the Project, and not the Project’s DLL by browsing for it.

While adding the reference you can find all the project for the current solution under “Projects” tab. Select the project that you want to refer. This way it will always build the referred Project first and then the current one (to resolve the dependency).

There’s another way of doing this. You can right click on the solution and select “Project Dependencies”. This window allows you to select the project and mark the projects it is dependent on.

Happy Learning! ?
DevsDaily | Azure DevOps

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