Notation Composer and Musician 233 maintenance release

Hi Sherry
I recently have a problem with a window popping up saying : " a sharing violation with accessing....." in Composer 2.3.3.
I opened a simple mid file in Composer, changed all actual pitches to another key , saved as MIDI and when re-opened in Composer,the above mentioned window pops up and the ( altered )file will not play.
Moreover, the same happens in all other Notation programs, and in my default synths( " no file detected " ) as well.
What am I doing wrong ?
Regards
Djim