diff --git a/manuskript/load_save/version_1.py b/manuskript/load_save/version_1.py
index 048ae26..6c4f91d 100644
--- a/manuskript/load_save/version_1.py
+++ b/manuskript/load_save/version_1.py
@@ -118,7 +118,14 @@ def saveProject(zip=None):
     # List of files to be moved
     moves = []
 
+    # MainWindow interaction things.
     mw = mainWindow()
+    project = mw.currentProject
+
+    # Sanity check (see PR-583): make sure we actually have a current project.
+    if project is None:
+        print("Error: cannot save project because there is no current project in the UI.")
+        return False
 
     # File format version
     files.append(("MANUSKRIPT", "1"))
@@ -295,10 +302,8 @@ def saveProject(zip=None):
 
     files.append(("settings.txt", settings.save(protocol=0)))
 
-    project = mw.currentProject
-
     # We check if the file exist and we have write access. If the file does
-    # not exists, we check the parent folder, because it might be a new project.
+    # not exist, we check the parent folder, because it might be a new project.
     if os.path.exists(project) and not os.access(project, os.W_OK) or \
        not os.path.exists(project) and not os.access(os.path.dirname(project), os.W_OK):
         print("Error: you don't have write access to save this project there.")
diff --git a/manuskript/mainWindow.py b/manuskript/mainWindow.py
index aa74f6e..f05ea68 100644
--- a/manuskript/mainWindow.py
+++ b/manuskript/mainWindow.py
@@ -695,6 +695,7 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         # Clear datas
         self.loadEmptyDatas()
         self.saveTimer.stop()
+        self.saveTimerNoChanges.stop()
         loadSave.clearSaveCache()
 
         self.breakConnections()
@@ -818,6 +819,13 @@ class MainWindow(QMainWindow, Ui_MainWindow):
         # risk a scenario where the timer somehow triggers a new save while saving.
         self.saveTimerNoChanges.stop()
 
+        if self.currentProject is None:
+            # No UI feedback here as this code path indicates a race condition that happens
+            # after the user has already closed the project through some way. But in that
+            # scenario, this code should not be reachable to begin with.
+            print("Bug: there is no current project to save.")
+            return
+
         r = loadSave.saveProject()  # version=0
 
         projectName = os.path.basename(self.currentProject)