diff --git a/CHANGELOG.md b/CHANGELOG.md
index 82832882..37ed263c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ CHANGELOG for FlatCAM Evo beta
 
 =================================================
 
+14.05.2023
+
+- Isolation Plugin, NCC Plugin and Find Optimal Plugin: fixed not finding the optimal tool diameter (the one that will isolate completely a Gerber object)
+
 05.05.2023
 
 - fixed an erroneous opening for a Gerber file generated by KiCAD 6.0.11, due of a rectangular flash being eliminated by the global unary_union operation
diff --git a/appPlugins/ToolIsolation.py b/appPlugins/ToolIsolation.py
index 3a2e3b50..4b773054 100644
--- a/appPlugins/ToolIsolation.py
+++ b/appPlugins/ToolIsolation.py
@@ -29,7 +29,7 @@ import builtins
 
 from appParsers.ParseGerber import Gerber
 from matplotlib.backend_bases import KeyEvent as mpl_key_event
-from camlib import grace
+from camlib import grace, flatten_shapely_geometry
 
 fcTranslate.apply_language('strings')
 if '_' not in builtins.__dict__:
@@ -1142,7 +1142,7 @@ class ToolIsolation(AppTool, Gerber):
 
         min_dict = {}
         idx = 1
-        w_geo = total_geo.geoms if isinstance(total_geo, (MultiLineString, MultiPolygon)) else total_geo
+        w_geo = flatten_shapely_geometry(total_geo)
         for geo in w_geo:
             for s_geo in w_geo[idx:]:
                 # minimize the number of distances by not taking into considerations
@@ -1271,16 +1271,17 @@ class ToolIsolation(AppTool, Gerber):
 
                     total_geo = MultiPolygon(total_geo)
                     total_geo = total_geo.buffer(0)
+                    total_geo = flatten_shapely_geometry(total_geo)
 
-                    if isinstance(total_geo, MultiPolygon):
-                        geo_len = len(total_geo.geoms)
-                        geo_len = (geo_len * (geo_len - 1)) / 2
-                    elif isinstance(total_geo, Polygon):
+                    geo_len = len(total_geo)
+                    if geo_len == 1:
                         msg = _("The Gerber object has one Polygon as geometry.\n"
                                 "There are no distances between geometry elements to be found.")
                         app_obj.inform.emit('[ERROR_NOTCL] %s' % msg)
                         return 'fail'
 
+                    geo_len = (geo_len * (geo_len - 1)) / 2
+
                     min_dict = {}
                     idx = 1
                     for geo in total_geo:
diff --git a/appPlugins/ToolNCC.py b/appPlugins/ToolNCC.py
index 765e638f..17d76b7e 100644
--- a/appPlugins/ToolNCC.py
+++ b/appPlugins/ToolNCC.py
@@ -972,6 +972,7 @@ class NonCopperClear(AppTool, Gerber):
 
         total_geo = MultiPolygon(total_geo)
         total_geo = total_geo.buffer(0)
+        total_geo = flatten_shapely_geometry(total_geo)
 
         if isinstance(total_geo, Polygon):
             msg = ('[ERROR_NOTCL] %s' % _("The Gerber object has one Polygon as geometry.\n"
@@ -979,8 +980,8 @@ class NonCopperClear(AppTool, Gerber):
             return msg, np.Inf
         min_dict = {}
         idx = 1
-        for geo in total_geo.geoms:
-            for s_geo in total_geo.geoms[idx:]:
+        for geo in total_geo:
+            for s_geo in total_geo[idx:]:
                 # minimize the number of distances by not taking into considerations
                 # those that are too small
                 dist = geo.distance(s_geo)
@@ -1112,20 +1113,21 @@ class NonCopperClear(AppTool, Gerber):
 
                     total_geo = MultiPolygon(total_geo)
                     total_geo = total_geo.buffer(0)
+                    total_geo = flatten_shapely_geometry(total_geo)
 
-                    if isinstance(total_geo, MultiPolygon):
-                        geo_len = len(total_geo.geoms)
-                        geo_len = (geo_len * (geo_len - 1)) / 2
-                    elif isinstance(total_geo, Polygon):
+                    geo_len = len(total_geo)
+                    if geo_len == 1:
                         app_obj.inform.emit('[ERROR_NOTCL] %s' %
                                             _("The Gerber object has one Polygon as geometry.\n"
                                               "There are no distances between geometry elements to be found."))
                         return 'fail'
 
+                    geo_len = (geo_len * (geo_len - 1)) / 2
+
                     min_dict = {}
                     idx = 1
-                    for geo in total_geo.geoms:
-                        for s_geo in total_geo.geoms[idx:]:
+                    for geo in total_geo:
+                        for s_geo in total_geo[idx:]:
                             if self.app.abort_flag:
                                 # graceful abort requested by the user
                                 raise grace
@@ -1537,6 +1539,7 @@ class NonCopperClear(AppTool, Gerber):
             self.app.inform.emit('[ERROR_NOTCL] %s: %s' % (_("Object not found"), str(self.obj_name)))
             return
 
+        # Check tool validity
         if self.ui.valid_cb.get_value() is True:
             # this is done in another Process
             self.find_safe_tooldia_multiprocessing()
diff --git a/appPlugins/ToolOptimal.py b/appPlugins/ToolOptimal.py
index fb46f6ce..586a675a 100644
--- a/appPlugins/ToolOptimal.py
+++ b/appPlugins/ToolOptimal.py
@@ -9,7 +9,7 @@ from PyQt6 import QtWidgets, QtCore, QtGui
 from appTool import AppTool
 from appGUI.GUIElements import VerticalScrollArea, FCLabel, FCButton, FCFrame, GLay, FCComboBox, FCCheckBox, \
     FCEntry, FCTextArea, FCSpinner, OptionalHideInputSection
-from camlib import grace
+from camlib import grace, flatten_shapely_geometry
 
 import logging
 import numpy as np
@@ -253,24 +253,25 @@ class ToolOptimal(AppTool):
                     _("Optimal Tool. Creating a buffer for the object geometry."))
                 total_geo = MultiPolygon(total_geo)
                 total_geo = total_geo.buffer(0)
+                total_geo = flatten_shapely_geometry(total_geo)
 
-                if isinstance(total_geo, MultiPolygon):
-                    geo_len = len(total_geo.geoms)
-                    geo_len = (geo_len * (geo_len - 1)) / 2
-                else:
+                geo_len = len(total_geo)
+                if geo_len == 1:
                     app_obj.inform.emit('[ERROR_NOTCL] %s' %
                                         _("The Gerber object has one Polygon as geometry.\n"
                                           "There are no distances between geometry elements to be found."))
                     return 'fail'
 
+                geo_len = (geo_len * (geo_len - 1)) / 2
+
                 app_obj.inform.emit(
                     '%s: %s' % (_("Optimal Tool. Finding the distances between each two elements. Iterations"),
                                 str(geo_len)))
 
                 plugin_instance.min_dict = {}
                 idx = 1
-                for geo in total_geo.geoms:
-                    for s_geo in total_geo.geoms[idx:]:
+                for geo in total_geo:
+                    for s_geo in total_geo[idx:]:
                         if app_obj.abort_flag:
                             # graceful abort requested by the user
                             raise grace