After upgrading my bbp-languages folder is gone.
I placed the file under /wp-content/plugins/bbpress/bbp-languages/bbpress-ja .mo but it doesn’t work anymore.

Where should I put the mo file?

[@jmdodd Moderator 12 years, 1 month ago]

bbPress 2.2 language files should go in /languages, not /bbp-languages, so: /wp-content/plugins/bbpress/languages/bbpress-ja.mo.

[@johnjamesjacoby Keymaster 12 years, 1 month ago]

To avoid this problem in the future, but them in:

/wp-content/languages/bbpress/bbpress-ja.*