Updates: Status: WontFix Comment #3 on issue 2279 by marcus.d...@gmail.com: Subject: [BUG]MultiByteFileStream(Object)>>error: on changes file throwing ***System Error Handling Failed*** running test coverage http://code.google.com/p/pharo/issues/detail?id=2279 Run Coverage should not be used on system classes, as this leads to all sort of problems. (e.g. Wrappers may use the code wrapped while executing...)