Problem with " invalid int "OS" help

Hi there .. how are you all brothers ?
In fact it's the first thread for me here so I need your help ..
I've a dictionary and when I tried to turn on Text to Speech then it gave me a message " Invalid int " OS"

I don't know what does it mean and what is the reason and how I can solve it please ????
I'm waiting for your help all ..:confused:
thanks again and again ..
yours Alnagar