Index: trunk/src_plugins/export_dxf/dxf.c
===================================================================
--- trunk/src_plugins/export_dxf/dxf.c	(revision 29222)
+++ trunk/src_plugins/export_dxf/dxf.c	(revision 29223)
@@ -336,7 +336,7 @@
 
 	if (pcb_cam_end(&dxf_cam) == 0)
 		if (!dxf_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "dxf cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "dxf cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 }
 
 static int dxf_parse_arguments(pcb_hid_t *hid, int *argc, char ***argv)
Index: trunk/src_plugins/export_excellon/excellon.c
===================================================================
--- trunk/src_plugins/export_excellon/excellon.c	(revision 29222)
+++ trunk/src_plugins/export_excellon/excellon.c	(revision 29223)
@@ -288,7 +288,7 @@
 
 	if (pcb_cam_end(&excellon_cam) == 0)
 		if (!excellon_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "excellon cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "excellon cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 
 	pcb_drill_uninit(&pdrills);
 	pcb_drill_uninit(&udrills);
Index: trunk/src_plugins/export_gcode/gcode.c
===================================================================
--- trunk/src_plugins/export_gcode/gcode.c	(revision 29222)
+++ trunk/src_plugins/export_gcode/gcode.c	(revision 29223)
@@ -363,7 +363,7 @@
 
 	if (pcb_cam_end(&gctx.cam) == 0)
 		if (!gctx.cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "gcode cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "gcode cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 }
 
 static int gcode_parse_arguments(pcb_hid_t *hid, int *argc, char ***argv)
Index: trunk/src_plugins/export_gerber/gerber.c
===================================================================
--- trunk/src_plugins/export_gerber/gerber.c	(revision 29222)
+++ trunk/src_plugins/export_gerber/gerber.c	(revision 29223)
@@ -675,7 +675,7 @@
 
 	if (pcb_cam_end(&gerber_cam) == 0)
 		if (!gerber_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "gerber cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "gerber cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 
 	pcb_drill_uninit(&pdrills);
 	pcb_drill_uninit(&udrills);
Index: trunk/src_plugins/export_png/png.c
===================================================================
--- trunk/src_plugins/export_png/png.c	(revision 29222)
+++ trunk/src_plugins/export_png/png.c	(revision 29223)
@@ -780,7 +780,7 @@
 
 	if (pcb_cam_end(&png_cam) == 0)
 		if (!png_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "png cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "png cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 }
 
 static int png_parse_arguments(pcb_hid_t *hid, int *argc, char ***argv)
Index: trunk/src_plugins/export_ps/eps.c
===================================================================
--- trunk/src_plugins/export_ps/eps.c	(revision 29222)
+++ trunk/src_plugins/export_ps/eps.c	(revision 29223)
@@ -348,7 +348,7 @@
 
 	if (pcb_cam_end(&eps_cam) == 0)
 		if (!eps_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "eps cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "eps cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 }
 
 static int eps_parse_arguments(pcb_hid_t *hid, int *argc, char ***argv)
Index: trunk/src_plugins/export_ps/ps.c
===================================================================
--- trunk/src_plugins/export_ps/ps.c	(revision 29222)
+++ trunk/src_plugins/export_ps/ps.c	(revision 29223)
@@ -662,7 +662,7 @@
 
 	if (pcb_cam_end(&ps_cam) == 0)
 		if (!ps_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "ps cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "ps cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 }
 
 static int ps_parse_arguments(pcb_hid_t *hid, int *argc, char ***argv)
Index: trunk/src_plugins/export_svg/svg.c
===================================================================
--- trunk/src_plugins/export_svg/svg.c	(revision 29222)
+++ trunk/src_plugins/export_svg/svg.c	(revision 29223)
@@ -366,7 +366,7 @@
 
 	if (pcb_cam_end(&svg_cam) == 0)
 		if (!svg_cam.okempty)
-			pcb_message(PCB_MSG_ERROR, "svg cam export for '%s' failed to produce any content\n", options[HA_cam].str);
+			pcb_message(PCB_MSG_ERROR, "svg cam export for '%s' failed to produce any content (layer group missing)\n", options[HA_cam].str);
 }
 
 static int svg_parse_arguments(pcb_hid_t *hid, int *argc, char ***argv)