diff --git a/CHANGELOG.md b/CHANGELOG.md
index 43e976df..14947636 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ CHANGELOG for FlatCAM beta
 28.08.2021
 
 - removed the setting for HDPI from Preferences and QSettings: QT6 does it automatically now
+- fixed a reported issue with the manual cutout in Cutout Plugin where adding more gaps will crash the app due of the manual geometry being a MultiPolygon and not a Polygon as it was assumed
+- fixed a reported bug in convert 2 geometry where a MultiLineString' object does not support item assignment“ error was issued
 
 26.08.2021
 
diff --git a/appPlugins/ToolCutOut.py b/appPlugins/ToolCutOut.py
index 54a571c6..73c2a02d 100644
--- a/appPlugins/ToolCutOut.py
+++ b/appPlugins/ToolCutOut.py
@@ -1623,7 +1623,16 @@ class CutOut(AppTool):
         if self.ui.gaptype_radio.get_value() == 'mb':
             mb_dia = self.ui.mb_dia_entry.get_value()
             b_dia = (self.cutting_dia / 2.0) - (mb_dia / 2.0)
-            self.mb_manual_solid_geo = self.flatten(unary_union(self.manual_solid_geo).buffer(b_dia).interiors)
+            # flaten manual geometry
+            unified_man_geo = unary_union(self.manual_solid_geo)
+            buff_man_geo = unified_man_geo.buffer(b_dia)
+            if isinstance(buff_man_geo, MultiPolygon):
+                int_list = []
+                for b_geo in buff_man_geo.geoms:
+                    int_list += b_geo.interiors
+            else:
+                int_list = buff_man_geo.interiors
+            self.mb_manual_solid_geo = self.flatten(int_list)
 
         self.cutting_gapsize = self.ui.gapsize.get_value()
 
diff --git a/app_Main.py b/app_Main.py
index 218bdd79..06541e28 100644
--- a/app_Main.py
+++ b/app_Main.py
@@ -4563,7 +4563,10 @@ class App(QtCore.QObject):
         for tooluid, dict_value in obj.tools.items():
             total_solid_geometry += deepcopy(dict_value['solid_geometry'])
             # clear the original geometry
-            dict_value['solid_geometry'][:] = []
+            if isinstance(dict_value['solid_geometry'], list):
+                dict_value['solid_geometry'][:] = []
+            else:
+                dict_value['solid_geometry'] = []
         obj.solid_geometry = deepcopy(total_solid_geometry)
         obj.plot()