Equisys technical notes

Technical guidance, explanations and fixes for our products

FIX: Error when sending from Zetadocs PDF Client with Office 365



This Zetadocs technical note applies to:

  • Zetadocs PDF 9.4 and above


When trying to send an email using the Zetadocs PDF client, you get the following error message "Email sending failed. There was an error communicating with the email application. Please check your Email Integration settings and try resending"


This can happen after you have upgraded from an older version of Office e.g. 2013 to Office 365. This error can also appear after upgrading from the 32bit version of Office or after performing an operating system upgrade from one version of Windows to another. The upgrades can result in some Microsoft registry entries becoming incorrect or missing.


Registry Editor warning

WARNING: Misusing Registry Editor can cause serious problems that may require you to reinstall your operating system. Equisys cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved.

  • Before going through the resolution shown below please, first of all, uninstall both Office 365 and the Zetadosc PDF client. Doing this reinstall can on occasion fix the issue, if that doesn't work please follow the resolution below.
  1. Open the Zetadocs PDF Client log, usually located at "C:\users\%username\AppData\Local\Temp\Zetadocs"
  2. Scroll down to see the latest error message and you should see the following:

    OpenCommunicationWithApplication() Failed to initialize communication with Outlook: System.InvalidCastException: Unable to cast COM object of type 'Microsoft.Office.Interop.Outlook.ApplicationClass' to interface type 'Microsoft.Office.Interop.Outlook._Application'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{00063001-0000-0000-C000-000000000046}' failed due to the following error: Interface not registered (Exception from HRESULT: 0x80040155).

    Note, the GUID here needs to match to be able to apply the resolution "{00063001-0000-0000-C000-000000000046}"
  3. Open the Registry Editor and do the following:
    1. Go to HKEY_CLASSES_ROOT\Interface\{00063001-0000-0000-C000-000000000046}\TypeLib
      1. Make a note of the Version attribute for later
      2. There is a GUID in the (Default) section, copy this.
    2. Look for that GUID in the HKEY_CLASSES_ROOT\TypeLib key
      1. Browse down to the version number you noted, and then go through the 0\Win64 keys. You will then see a file path to a file called MSOUTL.olb
  4. Make sure Outlook and Zetadocs PDF Client are closed.
  5. Download the regtlbv12 tool from here: https://files.equisys.com/pub/zetadocs/v9.4/Uploads/regtlibv12.zip
  6.  After downloading the regtlbv12 tool, run a command line as an administrator
    1. browse to the location where regtlb is downloaded to
    2. Run the command "regtlbv12.exe <path to MSOUTL.olb from registry>"
    3. This should return a success message.
  7. Start Zetadocs Client and try sending via Outlook again. This should now work.


The issue is resolved by the workaround detailed above.

Last updated: 5th July 2022  Author: MB/NT

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