[Pharo-users] Writing files - Mac OS or Pharo change?

Hi All, I'm porting (no big changes) code from pharo 4 to pharo5. In (*) the resulting file handle is nil. Not sure why, may it be something related to the recent Mac OS X upgrade to Sierra? The same code was working with Pharo 4 on El Capitan. The calling code is a Fuel serialization. openForWrite: writeMode "Open the file with the given name. If writeMode is true, allow writing, otherwise open the file in read-only mode." | fileHandle | (*) fileHandle := self basicOpenForWrite: writeMode. fileHandle ifNil: [ FileException signal: 'cannot open file: ', name ]. ^ (BinaryFileStream handle: fileHandle file: self forWrite: writeMode) register; yourself any advice is welcome. arturo