SAP Message RSAR145 - Error in the If function: incorrect value in ARG2 or 3: '&' / '&'

Diagnosis
An invalided value was recognized when the If-function in a formula wasevaluated.
Argument 2 (IF-branch) : ,,,,'&SYST-MSGV1&'
Argument 3 (ELSE-branch): ,,'&SYST-MSGV2&'
Possibly, a numerical value with decimal points was entered with acomma separating the decimals ( ' 9,99' ).
In order for a figure to be interpreted correctly, a period must beused to separate the decimals ( ' 9.99' ).

System Response
The system triggered an exception CX_SY_CONVERSION_NO_NUMBER.

Procedure
Correct the formula for the InfoObject.