In recent months, many browsers have begun to restrict various Flash and Java functions that the DeviantArt chat system relies upon to work properly. For now, if you wish to access the chat network, we can only ask you to consider doing so through a browser that still supports these features.
You may also wish to check if your browser allows you to re-enable these features manually, specifically for the URL "chat.deviantart.com" to ensure the security of your browser.
For information about how to do this in Chrome, you can follow along here: http://www.online-tech-tips.com/google-softwaretips/enable-flash-chrome-specific-websites/
For information about how to do this in Firefox, you can follow along here: https://helpx.adobe.com/flash-player/kb/enabling-flash-player-firefox.html
If you require more instructions, please reach out to your specific browser's help centers.