It likely to be a namespace not a reference problem.

In it's original location DataFileDataSet probably shared the same namepace as the rest of the project (MyProject). The namespace of the new project is different. Either change the namespace of DataFileDataSet to match the current project namespace or refer to it by the full identifier.

>I am trying to understand. In the solution where everything works, in the References section there is no entry for DataFileDataSet so I suppose it does not need to be referenced in the "new" solution.
>Otherwise I don't see what I am missing (I am sure I do; I just can't find it).
>Thank you.
>
>>You're missing a name space or a reference to an assembly.
>>
>>
>>>Hi,
>>>This must be so basic that I forgot how to do it <g>.
>>>I am moving some pages and code from one solution to another (in VS2012).
>>>One aspx page has the following line:
>>>

>>>private DataFileDataSet dstMyDataset;
>>>

>>>
>>>The DataFileDataSet is a dataset consisting of file:
>>>DataFileDataSet.xsd
>>>DataFileDataSet.Designer.cs
>>>DataFileDataSet.xsc
>>>DataFileDataSet.xss
>>>
>>>I copied the aspx page and all dataset files from one solution to another. And in the solution where everything works the intellisense when pointing to DataFileDataSet says "Class MyProject.DataFileDataSet represents the strongly typed in-memory cache of data.
>>>
>>>But in the new solution the "DataFileDataSet" shows with red squiggly underline and the message is that "type or namespace could not be found ..."
>>>
>>>What am I missing? How do I make the strongly typed dataset "working" in the new solution? TIA