How do you report a bug?

I found a bug in the Game Explorer. (An unplayable and unclickable move is suggested, circled in red.)

What move order got you to that? If it is reproducible then you could report it via the contact form.  https://support.chess.com/customer/portal/emails/new

@Martin_Stahl,

one move order is 1. d4 d5 2. Nc3 e6 3. e4 Nf6 4. Bg5 dxe4.

The problem doesn't exist on v3 and when I tried it the first time on v2 it didn't happen.  Accidentally reloaded the page and now it happens. 

Will try again when I get to my computer and see if I can recreate. 

Well, it happened on my home machine too. You can report via the following, though I don't know if it will be fixed since most work is going into v3.

https://support.chess.com/customer/portal/emails/new

that is really strange

    http://www.chess.com/forum/search?keyword=Bug+on+chess.com