Cannot write email body in OWA with Exchange 2013 SP1 CU6

Hi,

I have a problem with Exchange 2013 SP1 with CU6.

All of OWA user cannot write in the body of email. They can write the Object and the recipient but they cannot select body and write the body message. We have try with multiple Web brother and desactivate all Add-on but the problem still there...

The only way that works is to respond to an email, and in that case, it's working, we can write normally in the body of email.

Have you an idea ?

Thanks in advance!

Sebastien