I often go to chinese.stackexchange.com as I am learning Chinese.

Yesterday, I could not log in. I thought maybe they are doing maintenance work. Today, I still can't log in. The log in button is dead, no reaction.

At the top of the page, there are 2 fields where you can see comments or criticisms on threads you have answered and changes in your score. These are also dead.

I started Ubuntu in recovery mode, ran package check, ran fsck, did not get any problems.

I tried this using Firefox and Chrome.

Then I started an older Toshiba laptop which also has Ubuntu 16.04

I logged in no problem.

Here at work on this computer I also cannot log in to chinese.stackexchange.com

Does anyone have an explanation for this? Some kind of hack? stackexchange's server is faulty?

Hi...

Out of curiosity, Are you able to right click on the log in button and bring up the log in page in another tab? Did you try flushing out the cache and deleting cookies? Did you disable Javascript?

Also, in case you don't find a resolution here, you can try using the Chinese StackExchange support page here.

Regards...

I did not knowingly disable java script.

I did delete all cookies. I don't know how to flush the cache.

If I right click the log in button I cannot bring up the log in page in another window. I can see the source code.

This is weird, it works on 1 laptop, but not on this desktop or my usual laptop.

Using the same OS and browser/s? Any browser plugins that might block scripts?

You can use firebug or chrome's developer tools to see which element/s fails to load.

At work I use Fedora 23, at home both laptops have Ubuntu 16.04. I update the software very regularly.

There may be browser plugins which cause problems, but I have not changed anything recently. 2 days ago, I did not have this problem.

Hi...

A quick Google search on "how to flush the cache in [browser name]" should give you the relevant instructions. Also, did you install any updates on these systems at the time this started happening. Please post back with what firebug or the developer tools show.

I agree, this doesn't make any sense at the moment.

Regards...

I flushed the cache via Firefox Settings and installed firebug. Also, I checked that javascript is enabled. about:config in Firefox gets me to the page where I can enable or disable things. Javascript is enabled.

Firebug does not show any error.

I keep most google sites blocked in hosts, because I live in China. Every time a site links to google, the load time approaches infinity, so I just point all these to 127.0.0.1 Google and China are not friends.

However, I have been doing this for a long time before this problem arose. Also, I have a vpn, so with vpn enabled I should be able to log in, but that also does not work.

Just thought I'd finish this: the situation was, I could not log in to chinese.stackexchange.com on Ubuntu, but it worked ok on a windows machine.

I am in China, so weird things happen. google is blocked for the most part. Many, many pages link to google sites. They slow down load times for webpages a lot.

I was given the tip, put such sites in hosts: 127.0.0.1 www.anysite.any

I think this makes the browser look in the localhost, it finds nothing and moves on instead of waiting forever.

Yesterday, on an idea, I commented out all these lines in hosts. Bam, I could log in again on Ubuntu, the first time in months.

Weirder still: I gradually uncommented the lines to see if I could find what was the problem. All the lines are now uncommented and I can still login ok.

All's well that ends well, but I don't understand it!

Did you [not] exit&restart the browser? Here's a TL;dr that, way at the end, says:
"Some applications such as Firefox seem to cache this information and may need to be restarted"
(or, less-likely and more-obscure, this /etc/nscd.conf: enable-cache hosts no)