I am unable to use the Japanese version of Stack Overflow.

I have an account on here.

The problem I am facing is this: Whenever I try to upvote/downvote or post questions/answers, I get an error:

Bad request-invalid url

Http 400 error: the requested url is invalid


How can I fix the issue?

  • Can't reproduce, was able to upvote that question now. What browser/OS? Do you see errors in your console? Dec 20, 2015 at 13:17
  • I am on opera mini 6 OS Java
    – starkeen
    Dec 20, 2015 at 13:20
  • 1
    Opera Mini is not supported. Use a common browser instead. Dec 20, 2015 at 13:20
  • @ShadowWizard Does this version of SO work on java OS devices?
    – starkeen
    Dec 20, 2015 at 13:28
  • If you'll have a standard browser like Chrome, the OS should not matter, as the browser should do all the hard work. (Mainly JavaScript rendering) Dec 20, 2015 at 13:29

1 Answer 1


According to Which browsers are officially supported, and what else do I need?:

Opera Mobile

  • Stack Overflow appears to function properly in 12.0.1
  • Explicitly unsupported: Opera Mini (source)

And from Unable to start a bounty using Opera Mini:

Unfortunately at the moment we don't support Opera mini.

Reason: a combination of amount of work required and amount of visitors using the browser.

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