Please, read
this before posting questions.
As of your question: Mibew Messenger is known to work fine in all modern browsers. If you face any troubles, write down step by step what you do. Write, what you expect to see. Write, what you actually see. Specify the verson of
all related software (from Mibew Messenger to server OS and web server to client OS and browser). Maybe in this case one will be able to answer.