We had a customer who was having an issue with Outlook 2016. They were getting a dialog box with the error: Invalid index. (Exception from HRESULT:0x8002000B(DISP_E_BADINDEX)).
I did a quick repair on the Outlook program, but this didn’t fix the issue. Others on the web found the issue resides in the Add-ins.
In Outlook >> File >> Options >> Add-ins we discovered a “Sage” add-in. They use Sage for their banking but felt that shouldn’t be attached to their email. We turned off the “Sage” add-in and we were no longer getting the issue.
Let us know if this helps you…