This error indicates to an UTF-8 issue where the license server tries to transmit accented letters (ä,ö,ü,à, etc.) while a returning procedure.

Enclosed you can find the servercomptranutil program which can process umlauts like (ä,ö,ü, etc.). Please copy both files into the "bin-folder" of the license server directory and execute the command below.

servercomptranutil -new -transaction https://license.ecognition.com/flexnet/services/ActivationService -return <FulfillmentID>