I have a task pane (desktop) Office add-in built with the latest VS 2015 template for Excel and Word add-ins. When I open the file, the add-in task pane is not visible. My users need to click a button on the toolbar to open it, which they complain about.

In addition, I save the document with the task pane expanded but it does not affect that behavior. I remember a previous version of the add-in manifest (when it was called app for Office) kept the pane open but I upgraded it so I can use custom tabs in the Office ribbon.

Can I make the task pane stay expanded when the document or worksheet load?