karthikp wrote:I hope this isn't considered necro-bumping (at least not in a bad way), but I solved this problem just now and figured I'd document it.

You can't close a zeroed out investment account in the Institutions panel because the securities under that account haven't been closed in the Investments panel. First, configure kmymoney to uncheck General > Filter > Do not show zero balance equities. Now, go to Investments and go to the Equities tab. Select the investment account you're trying to close. You'll see the names of equities under this account. If the Quantity and Value are zero (as they should be, since the account is zeroed out), you should be able to right-click and select close account for the equity. Once you do this, you can go back to Institutions and close the investment accounts you were previously unable to close.

Hope this helps!