SAP Message /POSDW/PCA_SECURITY021 - SSFV: An exception (&1) has occurred during the string conversion

Diagnosis
An exception occurred in the Secure Store and Forward with VersionedKey function, causing the conversion of the encrypted entity from abinary format (HEX) to CHAR format to fail. The exception code stated inthe error message gives a first indication of the reason for the error.The following exception codes are possible in the case in hand:
'1' : Error during conversion
'2' : Internal error

System Response
The system terminates the process.

Procedure
An analysis of this error requires knowledge of internal processinglogic in the SAP system, meaning that the user cannot generally examinethe error.
Depending on the exception code, the following measures can be taken toeliminate the error:
'1' : Report the problem to SAP Support under the componentBW-BCT-ISR-PIPE.
'2': Report the problem to SAP Support under the componentBC-SEC-SSF.