Error while using message tokens

Hi All,

We have a requirement to validate maximum duration limit by storing the max limit in a UDT. We have defined an Error Message and a message token which picks the value from the Entry Validation Fast Formula and throws the message when the error is encountered. But while adding an absence, I'm getting the error "Contact your absence administrator with the following details: Module AbsenceEval, Method validateUsingFormulaFromUi and Error Exception occurred during validation formula execution. java.math.BigDecimal cannot be cast to java.lang.String." instead of the configured error message.

Please note that the issue is not appearing when I don't use message tokens. Below is the formula code I'm using. What mistake I'm doing here?