VSTO Error CS1760 stdole.dll RRS feed

  • Question

  • There is a VSTO Excel project:

    I would like to send an email with outlook but clearly, some assemblies are missing:

    So I decided to add a reference:

    Adding the reference:

    The Interop.Outlook appears in the References

    As soon as I add a reference the Outlook keyword and other keywords are fine:

    Visual studio is not complaining about the Outlook keyword anymore.

    However, Building the project produces the following error:


    Assemblies 'C:\WINDOWS\assembly\GAC\stdole\7.0.3300.0__b03f5f7f11d50a3a\stdole.dll' and 'C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE\PublicAssemblies\stdole.dll' refer to the same metadata but only one is a linked reference (specified using /link option); consider removing one of the references.ExcelAddIn1C:\Users\lt5244\source\repos\ExcelAddIn1\ExcelAddIn1\CSC 1 Active

    What should I do please?

    • Moved by CoolDadTx Thursday, February 15, 2018 3:36 PM Office related
    Thursday, February 15, 2018 3:29 PM

All replies

  • Anyone please?
    Friday, February 16, 2018 9:19 AM
  • Hello btsDeveloper,

    If you tried to remove all references of Outlook and stdole and re-add reference to Outlook, would this issue still exist?

    Best Regards,


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    Wednesday, February 21, 2018 8:40 AM