There are some other people with the same problem. Are you on Windows 10 by chance?
Chess.com menu disappears when I go to Live Chess

Nope - Windows 7 with Google Chrome. Thank you for taking a look at this. As I said, it just started happening a few days ago.

IE may help with troubleshooting but isn't a preferred browser. Just yrying to see if Chrome is having issues. Other people with a similar issue were on Chrome on Windows 10, though on that OS at least one member had the same problem on other browsers.

I saw an additional post where clearing caches was recommended. I just tried that, but it did not fix the issue.

Yeah that was my suggestion yesterday thinking some old scripts got cached. Now I'm thinking it is a problematic Windows update but not sure since I haven't updated that recently
There is a known certificate issue with GlobalSign that should be fixed in the next few days (not site related exactly but caused by the certificate authority) that may be related but your symptoms, along with others with the issue, isn't the same as what I've seen on the certificate front.
Most members that have reported it have been on Windows 10 and Chrome.
What AV are you using? Also, do you have any plugins installed on Chrome?

Interesting fact: If I right-click on "Custom Challenge" and choose "Open in new tab", then the new tab has the Custom Challenge options. The same does NOT work for the issue with the chess.com menu.

There were some windows updates installed recently...in fact, one of them could easily be the problem, given the timing. I have some plugins installed on Chrome, yes. Only active ones are AdBlock (which I did try turning off) and Office Online. Not sure what you are asking re: AV. What is AV?

Can you go ahead and test with IE?
The other common factor is every post that I have seen is with a basic member so I wonder if it might be related to the ad code?

Happens on IE as well, which means that it is not the plugins. I don't have any plugins installed there. Maybe a mix of ad code and the windows update, whatever it was?

Possibly. I've asked about it. It is possible staff is aware already but if not, I've made them aware

... Not sure what you are asking re: AV. What is AV?
Anti-virus. Some have hooks into the browsers for scanning links for malicious code. The certificate issue could also impact that process, as well as the AV causing an issue.

Oh, right. I have Kaspersky running as the AV. Did you see my post re: right-clicking on the Custom Challenge and going to a new tab? Don't know if that helps, but I found it interesting.

Yeah, sounds almost like some of the scripts are being blocked. One other post from yesterday did have some javascript errors .... so it is very possible it is related to the ad code or hooks into that code.

Question, does disabling your ad block and Kapersky at the same time, temporarily of course, make any difference?
This is a recent thing - last week it was working as designed (maybe even earlier this week?). In the new chess.com, when I choose Play/Live Chess from the menu on the left, I get to the Live Chess screen BUT:
1. The left-hand menu (all of it) disappears. No Home, Play, Learn, Share, Help, etc.
2. When I click on "Custom Challenge" or "See Open Challenges", nothing happens.
Help? I turned off AdBlock, and it did not seem to help at all.
EDIT: I am using Google Chrome as the browser, and Windows 7 as the OS.
Thanks,
Jonathan