Hi, We write code and comment in English, so only ascii characters are used. For string we also use English, and when translation is needed we use catalog of messages as gettext, where the non ascii strings are externally represented. So most of the time we only use ascii characters in our code. However, if a developer writes non ascii character in a method, fileout may just break. The problem is described and related to MultiByteFileStream: https://pharo.fogbugz.com/f/cases/14462 I check with Squeak4.5, although I cannot enter non-ascii character (but that's another problem, probably related to the VM I am using not suited to Squeak) I have no error when fileout the same class with non-ascii character in method body. The MultiByteFileStream seems quite different, I don't know the history of changes in these two method versions but changed in Squeak version seems a bit newer. The changes may not be trivial because it involves the whole class hierarchy. Hilaire -- Dr. Geo - http://drgeo.eu iStoa - http://istoa.drgeo.eu