diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c212d4e..dc622ade 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,12 @@ CHANGELOG for FlatCAM Evo beta
 
 =================================================
 
+01.03.2023
+
+- in Tool Milling made sure that deleting the only tool will not crash the application
+- added a new parameter in Preferences to control the number of processes created by the Pool() - more processes better performance but also a lot of memory consumed
+- made sure that the display of messages in the Status Bar is done asap
+
 19.01.2023
 
 - added a new method for bilinear interpolation
diff --git a/appGUI/preferences/PreferencesUIManager.py b/appGUI/preferences/PreferencesUIManager.py
index f6b9e37e..4f545226 100644
--- a/appGUI/preferences/PreferencesUIManager.py
+++ b/appGUI/preferences/PreferencesUIManager.py
@@ -71,6 +71,7 @@ class PreferencesUIManager(QtCore.QObject):
             "global_send_stats": self.ui.general_pref_form.general_app_group.send_stats_cb,
 
             "global_worker_number": self.ui.general_pref_form.general_app_group.worker_number_sb,
+            "global_process_number": self.ui.general_pref_form.general_app_group.process_number_sb,
             "global_tolerance": self.ui.general_pref_form.general_app_group.tol_entry,
 
             "global_compression_level": self.ui.general_pref_form.general_app_group.compress_spinner,
diff --git a/appGUI/preferences/general/GeneralAppPrefGroupUI.py b/appGUI/preferences/general/GeneralAppPrefGroupUI.py
index 16d67696..16453bf7 100644
--- a/appGUI/preferences/general/GeneralAppPrefGroupUI.py
+++ b/appGUI/preferences/general/GeneralAppPrefGroupUI.py
@@ -119,16 +119,29 @@ class GeneralAppPrefGroupUI(OptionsGroupUI):
             _("The number of Qthreads made available to the App.\n"
               "A bigger number may finish the jobs more quickly but\n"
               "depending on your computer speed, may make the App\n"
-              "unresponsive. Can have a value between 2 and 16.\n"
+              "unresponsive. Can have a value between 2 and 32.\n"
               "Default value is 2.\n"
               "After change, it will be applied at next App start.")
         )
         self.worker_number_sb = FCSpinner()
-        self.worker_number_sb.set_range(2, 16)
+        self.worker_number_sb.set_range(2, 32)
 
         grid1.addWidget(self.worker_number_label, 2, 0)
         grid1.addWidget(self.worker_number_sb, 2, 1)
 
+        # Process Numbers
+        self.process_number_label = FCLabel('%s:' % _('Process number'))
+        self.process_number_label.setToolTip(
+            _("The number of processes.\n"
+              "A larger number may improve performance but it will require more memory.\n"
+              "After change, it will be applied at next App start.")
+        )
+        self.process_number_sb = FCSpinner()
+        self.process_number_sb.set_range(2, 32)
+
+        grid1.addWidget(self.process_number_label, 4, 0)
+        grid1.addWidget(self.process_number_sb, 4, 1)
+
         # Geometric tolerance
         tol_label = FCLabel('%s:' % _("Geo Tolerance"))
         tol_label.setToolTip(_(
@@ -143,8 +156,8 @@ class GeneralAppPrefGroupUI(OptionsGroupUI):
         self.tol_entry.setSingleStep(0.001)
         self.tol_entry.set_precision(6)
 
-        grid1.addWidget(tol_label, 4, 0)
-        grid1.addWidget(self.tol_entry, 4, 1)
+        grid1.addWidget(tol_label, 6, 0)
+        grid1.addWidget(self.tol_entry, 6, 1)
 
         # Portability
         self.portability_cb = FCCheckBox('%s' % _('Portable app'))
@@ -153,7 +166,7 @@ class GeneralAppPrefGroupUI(OptionsGroupUI):
                                          "which means that the preferences files will be saved\n"
                                          "in the application folder, in the lib\\config subfolder."))
 
-        grid1.addWidget(self.portability_cb, 6, 0, 1, 2)
+        grid1.addWidget(self.portability_cb, 8, 0, 1, 2)
 
         # Verbose Log
         self.verbose_label = FCLabel('%s:' % _('Verbose log'))
@@ -166,8 +179,8 @@ class GeneralAppPrefGroupUI(OptionsGroupUI):
         self.verbose_combo = FCComboBox2()
         self.verbose_combo.addItems(['0','1', '2'])
 
-        grid1.addWidget(self.verbose_label, 8, 0)
-        grid1.addWidget(self.verbose_combo, 8, 1)
+        grid1.addWidget(self.verbose_label, 10, 0)
+        grid1.addWidget(self.verbose_combo, 10, 1)
 
         # #############################################################################################################
         # Grid0 Frame
diff --git a/appMain.py b/appMain.py
index 547ae5e2..93482057 100644
--- a/appMain.py
+++ b/appMain.py
@@ -634,7 +634,7 @@ class App(QtCore.QObject):
         # ###########################################################################################################
         # ###################################### CREATE MULTIPROCESSING POOL #######################################
         # ###########################################################################################################
-        self.pool = Pool()
+        self.pool = Pool(processes=self.options["global_process_number"])
 
         # ###########################################################################################################
         # ###################################### Clear GUI Settings - once at first start ###########################
@@ -1564,7 +1564,7 @@ class App(QtCore.QObject):
         """
         self.pool.close()
 
-        self.pool = Pool()
+        self.pool = Pool(processes=self.options["global_process_number"])
         self.pool_recreated.emit(self.pool)
 
         gc.collect()
@@ -2743,6 +2743,7 @@ class App(QtCore.QObject):
             # is not printed over and over on the shell
             if msg != '' and shell_echo is True:
                 self.shell_message(msg)
+        QtWidgets.QApplication.processEvents()
 
     def info_shell(self, msg, new_line=True):
         """
diff --git a/appPlugins/ToolMilling.py b/appPlugins/ToolMilling.py
index 11fc626b..fb4d6cee 100644
--- a/appPlugins/ToolMilling.py
+++ b/appPlugins/ToolMilling.py
@@ -402,7 +402,7 @@ class ToolMilling(AppTool, Excellon):
             _("Copy"), self.on_tool_copy,
             icon=QtGui.QIcon(self.app.resource_location + "/copy16.png"))
         self.ui.geo_tools_table.addContextMenu(
-            _("Delete"), lambda: self.on_tool_delete(clicked_signal=None, all_tools=None),
+            _("Delete"), lambda: self.on_tool_delete(all_tools=None),
             icon=QtGui.QIcon(self.app.resource_location + "/trash16.png"))
 
         # #############################################################################################################
diff --git a/appPool.py b/appPool.py
index 464fcbac..6333159c 100644
--- a/appPool.py
+++ b/appPool.py
@@ -23,7 +23,7 @@ class WorkerPool(QtCore.QObject):
 
     def __init__(self):
         super(WorkerPool, self).__init__()
-        self.pool = Pool(cpu_count())
+        self.pool = Pool(int(cpu_count() / 4))
 
     def add_task(self, task):
         print("adding task", task)
diff --git a/defaults.py b/defaults.py
index 4c79a9d0..3cd24993 100644
--- a/defaults.py
+++ b/defaults.py
@@ -100,6 +100,7 @@ class AppDefaults:
         "global_version_check": True,
         "global_send_stats": True,
         "global_worker_number": int((os.cpu_count()) / 2) if os.cpu_count() > 4 else 1,
+        "global_process_number": int((os.cpu_count()) / 4) if os.cpu_count() > 4 else 1,
         "global_tolerance": 0.005,
 
         "global_save_compressed": True,