diff --git a/CHANGELOG.md b/CHANGELOG.md
index a35ee58..b4a8f26 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,11 @@ Activate / deactivate layer opaticty according to prefix
 Activate / deactivate all masks using MA layers
 -->
 
+0.9.5
+
+- added: `check for problems` button also propose to run GP toolbox's file checker (if addon is enabled) to perform generic file checks
+- changed: `check for problems` skip check for opacity on 'MA_' prefixed layers
+
 0.9.4
 
 - feat: `Renumber files on disk` option using number in file outputs (under advanced gp render options) 
diff --git a/OP_check_scene.py b/OP_check_scene.py
index 2e2ef80..c28e29f 100644
--- a/OP_check_scene.py
+++ b/OP_check_scene.py
@@ -40,7 +40,7 @@ def check_layer_state(pool=None, reports=None):
                 #     mlinvert = ' <>' if ml.invert else ''
                 #     reports.append(f' - {ml.name}{mlstate}{mlinvert}')
 
-            if l.opacity != 1:
+            if l.opacity != 1 and not l.info.startswith('MA_'):
                 reports.append(f'{ob.name} > {l.info} > opacity {l.opacity}')
 
             # if l.use_lights:
@@ -124,9 +124,13 @@ class GPEXP_OT_check_render_scene(bpy.types.Operator):
 
         if not reports:
             self.report({'INFO'}, 'All OK !')
-        else:
-            fn.show_message_box(_message=reports, _title='Potential Problems list')
+            reports.append('Everything Ok !')
 
+        if hasattr(bpy.types, 'GP_OT_file_checker'):
+            # propose to run toolbox checker if exists
+            reports.append(['gp.file_checker', 'Run GP_toolbox File Checker', 'SCENE_DATA'])
+
+        fn.show_message_box(_message=reports, _title='Potential Problems list')
         return {"FINISHED"}
 
 classes=(
diff --git a/__init__.py b/__init__.py
index f1557c1..4b10822 100644
--- a/__init__.py
+++ b/__init__.py
@@ -2,7 +2,7 @@ bl_info = {
     "name": "GP Render",
     "description": "Organise export of gp layers through compositor output",
     "author": "Samuel Bernou",
-    "version": (0, 9, 3),
+    "version": (0, 9, 5),
     "blender": (2, 93, 0),
     "location": "View3D",
     "warning": "",
diff --git a/fn.py b/fn.py
index 9ae0103..c0aac8e 100644
--- a/fn.py
+++ b/fn.py
@@ -835,8 +835,12 @@ def normalize_layer_name(layer, prefix='', desc='', suffix='', lower=True, dash_
                         print(f' - updated in {ob.name} modifier {m.name}')
                         m.layer = new
 
-## confirm pop-up message:
+""" # old show message gox without operator support
 def show_message_box(_message = "", _title = "Message Box", _icon = 'INFO'):
+    '''get a str to display or a list of [str, str]
+    can have an icon [[str, icon], str, [str, icon]]
+    '''
+
     def draw(self, context):
         for l in _message:
             if isinstance(l, str):
@@ -847,6 +851,31 @@ def show_message_box(_message = "", _title = "Message Box", _icon = 'INFO'):
     if isinstance(_message, str):
         _message = [_message]
     bpy.context.window_manager.popup_menu(draw, title = _title, icon = _icon)
+ """
+
+def show_message_box(_message = "", _title = "Message Box", _icon = 'INFO'):
+    '''Show message box with element passed as string or list
+    if _message if a list of lists:
+        if sublist have 2 element:
+            considered a label [text,icon]
+        if sublist have 3 element:
+            considered as an operator [ops_id_name, text, icon]
+    '''
+
+    def draw(self, context):
+        for l in _message:
+            if isinstance(l, str):
+                self.layout.label(text=l)
+            else:
+                if len(l) == 2: # label with icon
+                    self.layout.label(text=l[0], icon=l[1])
+                elif len(l) == 3: # ops
+                    self.layout.operator_context = "INVOKE_DEFAULT"
+                    self.layout.operator(l[0], text=l[1], icon=l[2], emboss=False) # <- highligh the entry
+    
+    if isinstance(_message, str):
+        _message = [_message]
+    bpy.context.window_manager.popup_menu(draw, title = _title, icon = _icon)
 
 
 def get_bbox_3d(ob):