diff --git a/bnpm/automatic_regression.py b/bnpm/automatic_regression.py
index 2d2903c..d1bb485 100644
--- a/bnpm/automatic_regression.py
+++ b/bnpm/automatic_regression.py
@@ -169,7 +169,7 @@ def __init__(
                 'kwargs_convergence': self.kwargs_convergence,
                 'n_jobs_optuna': self.n_jobs_optuna,
             }
-            self.callback_wandb = optuna.integration.WeightsAndBiasesCallback(
+            callback_wandb = optuna.integration.WeightsAndBiasesCallback(
                 metric_name="loss",
                 wandb_kwargs={
                     'project': self.wandb_project,
@@ -177,6 +177,13 @@ def __init__(
                 },
                 as_multirun=False,
             )
+            ## Make a safe version of the callback by putting it in a try-except block
+            def safe_callback(study, trial):
+                try:
+                    callback_wandb(study, trial)
+                except Exception as e:
+                    print(f'Error in wandb callback: {e}')
+            self.callback_wandb = safe_callback
         else:
             self.callback_wandb = None
 
@@ -295,7 +302,8 @@ def _objective(self, trial: optuna.trial.Trial) -> float:
             self.model_best = model
             self.params_best = kwargs_model
 
-        return loss
+        # return loss
+        return np.nan
 
     def fit(self) -> Union[sklearn.base.BaseEstimator, Optional[Dict[str, Any]]]:
         """