Trying to send (via email) a work order or any other APM objects, get an on-screen errot
Unable to initialize email system
The following error is registered in the logfile:
Error Ivara.Mail.OutlookMailPlugin.OutlookMail [13] OutlookMail::Initialize() - exception thrown EXCEPTION OCCURRED: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: Library not registered. (Exception from HRESULT: 0x8002801D (TYPE_E_LIBNOTREGISTERED)). at System.StubHelpers.StubHelpers.GetCOMIPFromRCW(Object objSrc, IntPtr pCPCMD, IntPtr& ppTarget, Boolean& pfNeedsRelease)
It is possible that multiple versions of Outlook are registered and an upgrade or downgrade did not clean up previous version keys appropriately.
This article (https://support.boyum-it.com/hc/en-us/articles/206772337-Outlook-issue-Unable-to-cast-COM-object-of-type-Microsoft-Office-Interop-Outlook-ApplicationClass-) identifies which keys should be listed under HKEY_CLASSES_ROOT\TypeLib\{00062FFF-0000-0000-C000-000000000046}
https://support.boyum-it.com/hc/en-us/articles/206772337-Outlook-issue-Unable-to-cast-COM-object-of-type-Microsoft-Office-Interop-Outlook-ApplicationClass-