Office authentication error when opening a project from Project Professional 2016 web application

Applies to: Project Professional 2016


You see the following error message when trying to launch a project from the Project web application:

"The server you are trying to access is using an authentication protocol not supported by this version of office."

Error message



This issue occurs with the .msi version of Project Professional 2016 after installing patch KB 4464584.


Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.

The issue can be resolved by adjusting the registry:

  1. Exit Project.
  2. Start Registry Editor. To do this, use one of the following procedures, as appropriate for your version of Windows.
    • Windows 10, Windows 8.1, and Windows 8: Press Windows Key + R to open the Run dialog box. Type regedit.exe, and then select OK.
    • Windows 7: Select Start, type regedit.exe in the search box, and then press Enter.
  3. Locate and then select the following registry subkey:
  4. Look for the value DisableSendIDCRLHeaderExceptOutlookOverride, if it does not exist then:
    1. On the Edit menu, point to New, and then select DWORD Value.
    2. Type DisableSendIDCRLHeaderExceptOutlookOverride, and then press Enter.
  5. In the Details pane, right-click DisableSendIDCRLHeaderExceptOutlookOverride, and then select Modify.
  6. In the Value data box, type 1, and then select OK.
  7. Exit the Registry Editor.

The issue should then be resolved.

Microsoft is researching this problem and will post more information in this article when the information becomes available.