Why do I encounter "Warning: popupmenu control requires a scalar Value" in openfig.m when I try to start my GUI?

When I start my GUI while in debugging mode "Stop on Warnings" (by typing the gui name "dashboard" in the command line), I receive the following message:

>> dashboard

Warning: popupmenu control requires a scalar Value Control will not be rendered until all of its parameter values are valid

> In openfig at 135

In gui_mainfcn>local_openfig at 286

In gui_mainfcn at 234

In dashboard at 49

Warning from openfig at 135

    figure(fig(i));

This message is generally repeated several times (5 times in this case), which doesn't correlate to the number of popup menus in my GUI (15). The GUI then proceeds to display and seems to work just fine.

When I looked in openfig as well as in gui_mainfcn, and dashboard, I didn't see any mention of a popup menu. When I checked the popup menus in my GUI .fig file using GUIDE, all of them had scalar values (1.0) specified.

Googling the warning message yielded no useful threads. I found one person who seemed to have a similar problem, but there was no suggested answer (<http://www.mathworks.com/matlabcentral/newsreader/view_thread/28242)>.

I'm using 2012b on a 64-bit system running Windows 7 Professional.

Can anyone explain this behavior to me? My GUI is very large and was written by someone else. I'm trying to fix some bugs, and was wondering if they may partially be related to this message.

Thanks!

Answer 1

[Walter Roberson]

At the command prompt, give the command

 dbstop if warning

and then open the figure. It should stop at the point where it attempts to set() a uicontrol's Value to a vector.

If there happens to be only one popupmenu then you could search the source code more directly.

Answer 2

[Vishal Rane]

The 'Value' property determines which of the elements in a cell array ('String' property of the popupmenu) will be displayed by default. Hence its value must be a scalar between 1 and numel(your_cell_array). Unless you give it a default value, it will keep giving you this warning. Also the popupmenu itself wil not appear on the default GUI, though it does appear if you set any of its properties later.