diff --git a/application/alembic/versions/database_v3.py b/application/alembic/versions/database_v3.py
index 4d890d9..9e7b595 100644
--- a/application/alembic/versions/database_v3.py
+++ b/application/alembic/versions/database_v3.py
@@ -25,12 +25,17 @@ def upgrade():
                 "game_state",
                 sa.String(length=25),
                 default=GameStates.NOT_STATE.value,
-                nullable=False,
+                nullable=True,
             ),
             insert_after="",
             insert_before="",
         )
 
+        # Set back to nullable and fill with a default value.
+        batch_op.alter_column(
+            "game_state", nullable=False, server_default=GameStates.NOT_STATE.value
+        )
+
     # ### end Alembic commands ###
 
 
diff --git a/application/alembic/versions/database_v4.py b/application/alembic/versions/database_v4.py
index 6af58d8..4866241 100644
--- a/application/alembic/versions/database_v4.py
+++ b/application/alembic/versions/database_v4.py
@@ -44,10 +44,8 @@ def upgrade():
                 "game_steam_build_branch",
                 sa.String(length=256),
                 default="public",
-                nullable=False,
+                nullable=True,
             ),
-            insert_after="public",
-            insert_before="public",
         )
 
         batch_op.add_column(
@@ -55,10 +53,18 @@ def upgrade():
                 "game_steam_build_id",
                 sa.Integer(),
                 default=-1,
-                nullable=False,
+                nullable=True,
             ),
-            insert_after=-1,
-            insert_before=-1,
+        )
+
+        # Set back to nullable and fill with a default value.
+        batch_op.alter_column(
+            "game_steam_build_branch", nullable=False, server_default="public"
+        )
+
+        # Set back to nullable and fill with a default value.
+        batch_op.alter_column(
+            "game_steam_build_id", nullable=False, server_default="-1"
         )
 
     op.create_index("ix_actions_action_id", "actions", ["action_id"], unique=False)
diff --git a/application/gui/launch.py b/application/gui/launch.py
index d98c836..c925d74 100644
--- a/application/gui/launch.py
+++ b/application/gui/launch.py
@@ -125,6 +125,17 @@ def initialize(self, with_server=False):
         initialization_data = None
 
         if with_server:
+            # Check that one is not already running.
+            is_already_there = None
+            is_already_there = self._globals._client.architect.get_health()
+            if is_already_there == "Alive":
+                message = QMessageBox()
+                message.setText(
+                    "Error: Unable to start. This application is already running!"
+                )
+                message.exec()
+                return
+
             # Launch Flask Server
             self._spawn_server_on_thread()