diff --git a/openml/tasks/functions.py b/openml/tasks/functions.py
index 4c0aeaf4a..c44d55ea7 100644
--- a/openml/tasks/functions.py
+++ b/openml/tasks/functions.py
@@ -90,7 +90,7 @@ def _get_estimation_procedure_list():
     procs_dict = xmltodict.parse(xml_string)
     # Minimalistic check if the XML is useful
     if "oml:estimationprocedures" not in procs_dict:
-        raise ValueError("Error in return XML, does not contain tag " "oml:estimationprocedures.")
+        raise ValueError("Error in return XML, does not contain tag oml:estimationprocedures.")
     elif "@xmlns:oml" not in procs_dict["oml:estimationprocedures"]:
         raise ValueError(
             "Error in return XML, does not contain tag "
@@ -106,10 +106,19 @@ def _get_estimation_procedure_list():
 
     procs = []
     for proc_ in procs_dict["oml:estimationprocedures"]["oml:estimationprocedure"]:
+        task_type_int = int(proc_["oml:ttid"])
+        try:
+            task_type_id = TaskType(task_type_int)
+        except ValueError as e:
+            warnings.warn(
+                f"Could not create task type id for {task_type_int} due to error {e}",
+                RuntimeWarning,
+            )
+            continue
         procs.append(
             {
                 "id": int(proc_["oml:id"]),
-                "task_type_id": TaskType(int(proc_["oml:ttid"])),
+                "task_type_id": task_type_id,
                 "name": proc_["oml:name"],
                 "type": proc_["oml:type"],
             }
@@ -124,7 +133,7 @@ def list_tasks(
     size: Optional[int] = None,
     tag: Optional[str] = None,
     output_format: str = "dict",
-    **kwargs
+    **kwargs,
 ) -> Union[Dict, pd.DataFrame]:
     """
     Return a number of tasks having the given tag and task_type
@@ -175,7 +184,7 @@ def list_tasks(
         offset=offset,
         size=size,
         tag=tag,
-        **kwargs
+        **kwargs,
     )
 
 
@@ -240,9 +249,18 @@ def __list_tasks(api_call, output_format="dict"):
         tid = None
         try:
             tid = int(task_["oml:task_id"])
+            task_type_int = int(task_["oml:task_type_id"])
+            try:
+                task_type_id = TaskType(task_type_int)
+            except ValueError as e:
+                warnings.warn(
+                    f"Could not create task type id for {task_type_int} due to error {e}",
+                    RuntimeWarning,
+                )
+                continue
             task = {
                 "tid": tid,
-                "ttid": TaskType(int(task_["oml:task_type_id"])),
+                "ttid": task_type_id,
                 "did": int(task_["oml:did"]),
                 "name": task_["oml:name"],
                 "task_type": task_["oml:task_type"],
@@ -330,7 +348,10 @@ def get_task(
     task
     """
     if not isinstance(task_id, int):
-        warnings.warn("Task id must be specified as `int` from 0.14.0 onwards.", DeprecationWarning)
+        warnings.warn(
+            "Task id must be specified as `int` from 0.14.0 onwards.",
+            DeprecationWarning,
+        )
 
     try:
         task_id = int(task_id)
@@ -466,9 +487,12 @@ def create_task(
     estimation_procedure_id: int,
     target_name: Optional[str] = None,
     evaluation_measure: Optional[str] = None,
-    **kwargs
+    **kwargs,
 ) -> Union[
-    OpenMLClassificationTask, OpenMLRegressionTask, OpenMLLearningCurveTask, OpenMLClusteringTask
+    OpenMLClassificationTask,
+    OpenMLRegressionTask,
+    OpenMLLearningCurveTask,
+    OpenMLClusteringTask,
 ]:
     """Create a task based on different given attributes.
 
@@ -519,5 +543,5 @@ def create_task(
             target_name=target_name,
             estimation_procedure_id=estimation_procedure_id,
             evaluation_measure=evaluation_measure,
-            **kwargs
+            **kwargs,
         )