I'm experiencing a strange issue with Redemption in a RDS setup. When running Outlook as an ordinary user I get the following exception when attempting to connect to the session:
System.Runtime.InteropServices.COMException (0x8000FFFF): Interface not supported at Redemption.IRDOSession.set_MAPIOBJECT(Object Value)
However, when running Outlook as Administrator (but with the same Exchange mailbox) there is no error and everything works. I have tried both with Exchange cached mode enabled and without, this does not seem to make any difference.
The C# code is like this: ... RDOSession session = RedemptionLoader.new_RDOSession(); session.MAPIOBJECT = applicationObject.Session.MAPIOBJECT; ...
Versions: Windows Server 2019, version 1809. Outlook 2019 MSO (16.0.10386.20017) 64-bit. Redemption 5.5.0.3218.
Any ideas would be welcome :)
Setting MAPIOBJECT on the main thread did not fix the error. However, deleting Registry key
"HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\PreviewHandlers\Microsoft Windows MAPI Preview Handler"
fixed it.
In my initial question I forgot to mention (sorry), that just before the Redemption exception there was a "Microsoft Office Outlook" popup saying “Either there is no default mail client or the current mail client cannot fulfill the message request”. So I guess that was causing the Remption exception, even if I still haven't figured out the root cause or why it worked when running as Administrator.