diff --git a/Tst/codeblockreusefeature/codeblockreusefeature.cfg b/Tst/codeblockreusefeature/codeblockreusefeature.cfg
index 1cd33b6279ee19e14574ffe91dd108966c589cc7..de7a3ccafa19a5b18be7b36d1a93360c604ae0b1 100644
--- a/Tst/codeblockreusefeature/codeblockreusefeature.cfg
+++ b/Tst/codeblockreusefeature/codeblockreusefeature.cfg
@@ -24,7 +24,7 @@ threadname = True
 [codereuse-preferences]
 main-window-height = 791
 main-window-width = 612
-paned-position-search = 309
-paned-position-command-code = 162
+paned-position-search = 406
+paned-position-command-code = 68
 paned-position-comment = 462
 
diff --git a/Tst/tst/data_model.py b/Tst/tst/data_model.py
index 2c795eaef9b5124a962ce024c38e87a277ec9360..48bf7b8386096aa8330333c9bb3edfca5f601a60 100644
--- a/Tst/tst/data_model.py
+++ b/Tst/tst/data_model.py
@@ -989,6 +989,10 @@ class TestSpecification:
 
     @precon_name.setter
     def precon_name(self, value: str):
+        if value == None:
+            value = "None"
+        else:
+            pass
         assert isinstance(value, str)
         self._precon_name = value
 
@@ -1016,6 +1020,10 @@ class TestSpecification:
 
     @postcon_name.setter
     def postcon_name(self, value: str):
+        if value == None:
+            value = "None"
+        else:
+            pass
         assert isinstance(value, str)
         self._postcon_name = value
 
diff --git a/Tst/tst/tst.py b/Tst/tst/tst.py
index e6debfe3e5286be79ca1f9f653c66b50bf971740..b7e8f509b2a491d0df6dd62ddc8ce0e60502bb34 100755
--- a/Tst/tst/tst.py
+++ b/Tst/tst/tst.py
@@ -196,7 +196,7 @@ class TstAppWindow(Gtk.ApplicationWindow):
     def __init__(self, logger=logger, *args, **kwargs):
         super().__init__(*args, **kwargs)
         self.logger = logger
-        self.logger.info('Initializing a instance of the class TstAppWindow')
+        self.logger.info('Initializing an instance of the class TstAppWindow')
         self.product_paths = []
 
         # actions
diff --git a/Tst/tst/view.py b/Tst/tst/view.py
index 22438eb08701ddc150bcde0918edf25b93439172..8bf2dcb2064bd14b9bb23062845b2b9493d61493 100644
--- a/Tst/tst/view.py
+++ b/Tst/tst/view.py
@@ -71,7 +71,7 @@ class Board(Gtk.Box):
     """
     def __init__(self, model, app, filename=None, logger=logger):
         """
-        When a instance is initialized:
+        When an instance is initialized:
         * a data model instance is created
         * the toolbar is created
         * a instance of a grid is added