Hi,
MSN client is a software which allows you to browse and manage your emails it does not have the option to block any antivirus or its functionality. Please check if there are any other third party malwares, antivirus or software's conflicting with your antivirus program and the chrome browser.
Thanks and regards
Mubarak
In order to see assistance on an account you believe may have been compromised please fill out the information at the following link:
https://support.live.com/eform.aspx?productKey=wlid&page=wlsupport_home_options_form_byemail&ct=eformts
We appreciate your continued support as we strive to provide you with the highest quality service available.