Exception for loading from file caught too

gui/installer.py

@@ -348,10 +348,15 @@ class ValidationWidget(QWidget):
         self.load_tapes_from_file()
 
     def load_tapes_from_file(self):
-        with open("./source/tapes.yaml", encoding="utf-8") as fp:
-            tapes = yaml.safe_load(fp)
+        try:
+            with open("./source/tapes.yaml", encoding="utf-8") as fp:
+                tapes = yaml.safe_load(fp)
+                self.load_tapes(tapes)
+
+        except yaml.scanner.ScannerError as e:
+            dlg = DebugDialog(f"Error applying yaml code:\n\n{str(e)}")
+            dlg.exec()
 
-        self.load_tapes(tapes)
 
     def load_tapes(self, tapes):
         self.tapes = tapes