EGL ??

How strange, I got a basic Hello Triangle working using X11 as a native window as per the normal GLES2.0 GoldBook example.

But the exact same code in my demo project, throws up a strange error

/*
	     * X11 native display initialization
	     */

	x_display = XOpenDisplay(NULL);
	
	if (x_display == NULL)
	{
		return ;
	}

	root = DefaultRootWindow(x_display);

	swa.event_mask  =  ExposureMask | PointerMotionMask | KeyPressMask;
	win = XCreateWindow(
	    x_display,
		root,
		0,
		0,
		state->width,
		state->height,
		0,
		CopyFromParent,
		InputOutput,
		CopyFromParent,
		CWEventMask,
		&swa);

	xattr.override_redirect = FALSE;
	XChangeWindowAttributes(x_display, win, CWOverrideRedirect, &xattr);

	hints.input = TRUE;
	hints.flags = InputHint;
	XSetWMHints(x_display, win, &hints);
	char* title = (char*)"x11 windpw";
	    // make the window visible on the screen
	XMapWindow(x_display, win);
	XStoreName(x_display, win, title);

	    // get identifiers for the provided atom name strings
	wm_state = XInternAtom(x_display, "_NET_WM_STATE", FALSE); <<<<<< This reports an error

	memset(&xev, 0, sizeof(xev));
	xev.type                 = ClientMessage;
	xev.xclient.window       = win;
	xev.xclient.message_type = wm_state;
	xev.xclient.format       = 32;
	xev.xclient.data.l[0]    = 1;
	xev.xclient.data.l[1]    = FALSE;
	XSendEvent(
	  x_display,
		DefaultRootWindow(x_display),
		FALSE,
		SubstructureNotifyMask,
		&xev);

The error returned in the output causing the app to shut down is

X Error of failed request: BadValue (integer parameter out of range for operation)
Major opcode of failed request: 1 (X_CreateWindow)
Value in failed request: 0x0
Serial number of failed request: 7
Current serial number in output stream: 12

So it appears X_CreateWindow is not happy.
x_display is a static pointer in global memory and it is cleared before use.
static Display* x_display = NULL;

x_display = XOpenDisplay(NULL); did seem to return a valid value, (it returns NULL if it fails)
root = DefaultRootWindow(x_display); also returned a value, though it was not the value I got from the Hello Triangle example ($de), this was ($222)
I set the demo window size the same as hello triangle 320x240 just to try to replicate all the conditions Hello Triangle had in the Demo.

Take note that the demo is a much larger project, so I expect location of the x_display would be different, but I sorta expected root to be the same for both examples.
Also these are initialization systems to get a screen to draw too, and in that sense both set ups are the 1st things the demo's do.

I'm a bit lost....any one got any ideas? Clearly something is different between the two projects but I am not sure what.