setStyleSheet: <no such value>

[Jakob Clausen]

Hi all.

I have a strange error. I have an application where some of the widgets will change border-color if some kind of property changes. It seems to run fine, but every once in a while the program crashes. Now I have the program crashing with the debugger running.
It reports setStyleSheet: <no such value>. What does that mean?
The affected code seems to be

void InputWidget::status()
{
    if (!database.connected(index))
    {
        setStyleSheet("border: 3px solid gray;");
        return;
    }

    //if (database.allConnected(index))
    {
        if (!alive)
        {
            setStyleSheet("border: 3px solid yellow;");
        }
        else
        if (!database.signalValid(index))
        {
            setStyleSheet("border: 3px solid red;");
        }
        else
        if (database.updated(index))
        {
            setStyleSheet("border: 3px solid green;");
        }
        else
        {
            setStyleSheet("border: 3px solid blue;");
        }
    }
    //else
    {
    //    setStyleSheet("border: 3px solid black;");
    }
}

The debug output is

And this is where the program stops.

Any idea, how I should proceed?