This is a run-time error. What it is telling you is that TextLabelVar
is being read before it has been initialised. And that means that the WM_MESSAGEFROMANOTHERWINDOW
case statement executed before WM_CREATE
.
From the comments you've assigned 0
to TextLabelVar
to suppress the warning, but then of course the call to SetWindowText
cannot succeed since the window handle you pass is 0
.
To tackle the problem you need to understand why WM_MESSAGEFROMANOTHERWINDOW
is being handled before WM_CREATE
.