Have you tried clearing your browser cache or trying a different browser?
Being that the issue seems to be related to just one EVC thread, it leads me to believe it may be a caching issue specific to that thread itself. That can happen sometimes if there is an image on the rendered HTML that is causing issues.
Have you tried using Chrome in 'Ingognito' mode? You do that by pressing Ctrl-Shift-N after launching Chrome. What that basically does is null out any previous caching, cookies, etc.
You can give that a try and then navigate to the EVC site in ingognito mode (note you will need to login) and then try the EVC operations that were failing originally in Chrome in standard mode. If they work, that likely means Chrome is in some bad state. If they don't work, or you encounter similar issues, it likely means that the issue is more network or hardware/OS specific.