Joanne,
I am a developer of an Excel add-in, and this 'second grey window' problem appeared about a year ago as part of a Windows or Office update.
Because Microsoft has a habit of introducing as many (or more) bugs than fixes, we have a habit of keeping some development computers around that don't accept automatic Office updates.
On Office 365 version 16.0.4429.1024, our add-in works correctly. (no second grey window)
On the most recent version of Office 365, launching our add-in causes a second grey window to be launched.
Exact same add-in; it is Microsoft Excel (or Windows) that changed.
For obvious reasons, advising our customers to 'disable our add-in' is not an acceptable solution.
Is it possible for Microsoft to isolate what changed in Excel?
and then either:
- Fix it (to work the way Excel has always worked in the past with add-ins)
or 2) At least let us developers know what changed, and how we can re-write our applications to work with Excel's (currently undocumented) revised code?
I notice that this happens only when opening an Excel file through Windows.
If you open Excel first, and then open the same Excel file, no second window appears.
We're getting requests for support from our customers, and don't know how to address this new bug.
Any advice?
Dean Ziegler
Systems2win