Hello everyone, I thing, there is a bug in WriteStream, but i'm not sure. When I look at this code, I guess aString is not always a String, and yesterday, I had a Text send to this method, which raised a DNU error. (in blue is what I have change to make it work in my case) WriteStream>>nextChunkPut: aString "Append the argument, aString, to the receiver, doubling embedded terminators." | i remainder terminator | terminator := $!. remainder := aString asString. [(i := remainder indexOf: terminator) = 0] whileFalse: [self nextPutAll: (remainder copyFrom: 1 to: i). self nextPut: terminator. "double imbedded terminators" remainder := remainder copyFrom: i+1 to: remainder size]. self nextPutAll: remainder. aString asString includesUnifiedCharacter ifTrue: [ self nextPut: terminator. self nextPutAll: ']lang['. aString asString writeLeadingCharRunsOn: self. ]. self nextPut: terminator. Is that a bug ? Regards, Ben