diff --git a/src/aiida_sssp_workflow/protocol/convergence.yml b/src/aiida_sssp_workflow/protocol/convergence.yml
index af8af6d..bd1c66e 100644
--- a/src/aiida_sssp_workflow/protocol/convergence.yml
+++ b/src/aiida_sssp_workflow/protocol/convergence.yml
@@ -40,7 +40,7 @@ fine:
 
     base:   # base parameters is inherit by other process
         occupations: smearing
-        degauss: 0.0125   
+        degauss: 0.0125
         smearing: fd
         conv_thr_per_atom: 1.0e-9
         kpoints_distance: 0.1  # fine protocol of qe -> gabriel
diff --git a/src/aiida_sssp_workflow/protocol/criteria.yml b/src/aiida_sssp_workflow/protocol/criteria.yml
index 52cb925..769c8ac 100644
--- a/src/aiida_sssp_workflow/protocol/criteria.yml
+++ b/src/aiida_sssp_workflow/protocol/criteria.yml
@@ -78,7 +78,7 @@ efficiency:
 
     eos:
         mode: 0
-        bounds: [0.0, 0.2]  
+        bounds: [0.0, 0.2]
         eps: 1.0e-3
 
     phonon_frequencies:
diff --git a/src/aiida_sssp_workflow/workflows/common.py b/src/aiida_sssp_workflow/workflows/common.py
index 9128997..284ac86 100644
--- a/src/aiida_sssp_workflow/workflows/common.py
+++ b/src/aiida_sssp_workflow/workflows/common.py
@@ -1,4 +1,7 @@
+from builtins import ConnectionError
 from typing import Optional
+from paramiko import ssh_exception
+
 
 from aiida import orm
 
@@ -40,8 +43,12 @@ def clean_workdir(node: orm.CalcJobNode) -> Optional[int]:
     # other subsequent calcjob as `parent_folder`, i.e PH calculation.
     cached_from = node.base.extras.get("_aiida_cached_from", None)
     if not cached_from:
-        node.outputs.remote_folder._clean()  # pylint: disable=protected-access
-        return node.pk
+        try:
+            node.outputs.remote_folder._clean()  # pylint: disable=protected-access
+        except ssh_exception.SSHException as exc:
+            raise ConnectionError("ssh error") from exc
+        else:
+            return node.pk
     else:
         return None
 
diff --git a/src/aiida_sssp_workflow/workflows/evaluate/_phonon_frequencies.py b/src/aiida_sssp_workflow/workflows/evaluate/_phonon_frequencies.py
index 31fbc7c..b761a7d 100644
--- a/src/aiida_sssp_workflow/workflows/evaluate/_phonon_frequencies.py
+++ b/src/aiida_sssp_workflow/workflows/evaluate/_phonon_frequencies.py
@@ -194,11 +194,15 @@ def finalize(self):
         """set ecutwfc and ecutrho"""
 
         if self.inputs.clean_workdir.value is True:
-            cleaned_calcs = operate_calcjobs(
-                self.node, operator=clean_workdir, all_same_nodes=False
-            )
-
-            if cleaned_calcs:
+            try:
+                cleaned_calcs = operate_calcjobs(
+                    self.node, operator=clean_workdir, all_same_nodes=False
+                )
+            except ConnectionError as exc:
+                self.logger.warning(
+                    f"clean remote workdir folder {self.inputs.clean_workir} failed: {exc}"
+                )
+            else:
                 self.report(
                     f"cleaned remote folders of calculations: {' '.join(map(str, cleaned_calcs))}"
                 )