Can you post details of error from function RP_ANSAL_FROM_WAGETYPES - details, error code, class, etc? From the error, press help to give details; navigate to give you error code. The error could be in the feature ANSAL, currency being not found or conversion error, etc.
Also in MP000800 program module, search for RP_ANSAL, it calls above function (in include MP000840). Navigate to the function by double click on the function. You can also navigate to the function code in txn SE37. Then set a break point at the beginning of the function. Then execute the error giving txn PA40 or PA30. Then in debug mode you can find the source of the error.