diff --git a/pylot/core/util/errors.py b/pylot/core/util/errors.py
index a6015e55..8805b488 100644
--- a/pylot/core/util/errors.py
+++ b/pylot/core/util/errors.py
@@ -24,3 +24,6 @@ class OverwriteError(IOError):
 
 class ParameterError(Exception):
     pass
+
+class ProcessingError(RuntimeError):
+    pass