[Chrome email]

I get this error code   

400. That’s an error.

The server cannot process the request because it is malformed. It should not be retried. That’s all we know.

[Adobe and McAfee?]

I downloaded a new version of Adobe and it also downloaded McAfee.  Also some of my dropdown menus are now invisible.  I'm old, not cyber savvy and I've tried other things, should I worry about the McAfee?  Is there a fix for the invisible menus?