Index: /trunk/src/VBox/Devices/Graphics/DevVGA-SVGA3d-ogl.cpp
===================================================================
--- /trunk/src/VBox/Devices/Graphics/DevVGA-SVGA3d-ogl.cpp	(revision 53347)
+++ /trunk/src/VBox/Devices/Graphics/DevVGA-SVGA3d-ogl.cpp	(revision 53348)
@@ -5177,5 +5177,5 @@
 
     Log(("vmsvga3dSetClipPlane cid=%x %d (%d,%d)(%d,%d)\n", cid, index, (unsigned)(plane[0] * 100.0), (unsigned)(plane[1] * 100.0), (unsigned)(plane[2] * 100.0), (unsigned)(plane[3] * 100.0)));
-    AssertReturn(index <= SVGA3D_CLIPPLANE_MAX, VERR_INVALID_PARAMETER);
+    AssertReturn(index < SVGA3D_CLIPPLANE_MAX, VERR_INVALID_PARAMETER);
 
     if (    cid >= pState->cContexts
Index: /trunk/src/VBox/Devices/Graphics/DevVGA-SVGA3d-win.cpp
===================================================================
--- /trunk/src/VBox/Devices/Graphics/DevVGA-SVGA3d-win.cpp	(revision 53347)
+++ /trunk/src/VBox/Devices/Graphics/DevVGA-SVGA3d-win.cpp	(revision 53348)
@@ -5136,5 +5136,5 @@
 
     Log(("vmsvga3dSetClipPlane %x %d (%d,%d)(%d,%d)\n", cid, index, (unsigned)(plane[0] * 100.0), (unsigned)(plane[1] * 100.0), (unsigned)(plane[2] * 100.0), (unsigned)(plane[3] * 100.0)));
-    AssertReturn(index <= SVGA3D_CLIPPLANE_MAX, VERR_INVALID_PARAMETER);
+    AssertReturn(index < SVGA3D_CLIPPLANE_MAX, VERR_INVALID_PARAMETER);
 
     if (    cid >= pState->cContexts