diff --git a/src/ansys/meshing/prime/internals/error_handling.py b/src/ansys/meshing/prime/internals/error_handling.py
index 8602f841db..0ddfbdf8c3 100644
--- a/src/ansys/meshing/prime/internals/error_handling.py
+++ b/src/ansys/meshing/prime/internals/error_handling.py
@@ -299,6 +299,7 @@
     ErrorCode.SOURCETARGETZONELETSNOTFIT: "Source and target zonelets do not fit to thin volume mesh.",
     ErrorCode.AUTOQUADMESHER_INVALIDMINMAXSIZES: "Min size is more than max size.",
     ErrorCode.AUTOQUADMESHER_NEGATIVEINPUTPARAMETER: "Input parameters contains negative value.",
+    ErrorCode.INVALIDFILEEXTENSIONFORFLUENTCASEEXPORT: "Provided file extension is invalid. If cff_format is set to False, then supported extensions are .cas and .cas.gz. If cff_format is set to True, then supported extension is .cas.h5 .",
 }
 
 prime_warning_messages = {