Customer is using XML inbound activity and parsing input file with some special characters in UTF-8 format. The issue is that these characters are not being converted properly to ASCII codes in the input stage. This is as observed in BeforeReadInput event.
However, these characters are converted correctly in the output stage (event AfterWrite Output).

Customer can use STRREPLACE with the UTF8 codes found for each character as:

STRREPLACE($String,"\xc3\xbc","ue");