diff --git a/artiq/gui/experiments.py b/artiq/gui/experiments.py
index 424852c95..a6d2c0b7e 100644
--- a/artiq/gui/experiments.py
+++ b/artiq/gui/experiments.py
@@ -302,6 +302,7 @@ class _ExperimentDock(QtWidgets.QMdiSubWindow):
         except:
             logger.error("Could not recompute arguments of '%s'",
                          self.expurl, exc_info=True)
+            return
         self.manager.initialize_submission_arguments(self.expurl, arginfo)
 
         self.argeditor.deleteLater()