Shouldn’t it be:
define( 'BB_LANG', 'ja' );
Underscore between BB and LANG?
And, you should be installing the language file in a “my-languages” folder, on the same level as my-plugins and my-templates.
Thanks. Sorry, that was my typo.
I have ‘define( ‘BB_LANG’, ‘ja’);’. The language files are installed and they are recognized.
I am trying to build in dual language support for the 1.0.1.
Its seems that neither bbPress Language Switcher by _ck_ nor User Languages by alex work on v.1.
Does anyone know if there is a work around for this?
Manually, I can define either, say, ‘ja’ or ‘en_US’ … but it does not seem possible to do any switching at all, either via user admin or Switcher bar.
I really am sorry to discover this as I was looking for dual language WordPress/bbPress integration and to be free of the bloated phpBB for ever.
Thank you.
This is currently a problem for me as well. Like nonegiven above, I need dual language WordPress/bbPress integration, i.e. I need the facility to be able to switch the language of the bbPress forum interface from within the forum interface. Ideally this could tie in to the user’s stated language preference, or the language of the referring webpage.
However, I can only currently change the interface language by changing the settings in the bb_config.php file. This changes the language of the interface globally, which.
Like nonegiven, I’ve tried the bbPress Language Switcher plugin by _ck_ as well as User Languages and these don’t seem to work on v1.
Unfortunately, this undermines the usefulness of bbPress for multilingual websites. 
Any chance that this will be on the roadmap for the future?
Do you have any programming resources or budget available? It’d be a pretty straightforward effort to upgrade the plugins to work with the latest bbPress version…
Thanks for the reply John.
I don’t have a budget for this, but I’d consider paying for it out of my own pocket if the cost was reasonable.
E-mail me at gruff udd prys at hotmail com (no spaces) if it’s something you’d be willing to take on.
Cheers.
Hi Johnhiler
I am also interested in the bbpress bilingual, can you help?
Please PM me with your suggestions/proposal much appreciated.
Hi guys!
I am having the same problem as well. Have any of you found a solution?
I ran into a filter problem when trying to change it for just on the admin side but if you just want to change the whole language of the forum, you easily can – Install / Change bbPress to a different language
Hi Ashfame! Thank you for your response. However I have done exactly as in the description of the link you posted. I have made a folder in my bb_press root folder called my-languages and inserted the sv_SE.mo file on to that folder. In the bb-config file I have changed the code string to
define( ‘BB_LANG’, ‘sv_SE)’ );
Still english on my forum.
What´s up with that?
Not sure! Recheck your steps.
Make sure you have uploaded to the right place. Make sure it is there.
Add the file is to be added in bb-config.php and not bb-config-sample.php
We can generally make mistakes of uploading it somewhere and then trying to figure it out. 
My bb-press root is in a map called “forum” and in that folder I have put the my-languages folder and inserted the sv_SV.mo i that folder. I have edited the bb-config.php only.
I think that I have gone trough these steps a thousend times.
Would i be possible that some code or something is blocking this thing out. I am using a copy of kakumei which I have edited to fit my design and there I have “manually” translated some of the english text that I found in the files. could that be a problem?
Hard coded translations can NEVER be translated by a .mo/.po language file, since there’s no indication of it needing a change.
Okej, I really cant figure this out and I really need to get this fixed, what do I do?
If you are looking for paid support, then you can contact me personally – http://blog.ashfame.com/contact-ashfame/
Finally i found a solution!
Apparently your wordpress installation must have the same language as your BBpress for it to take action, so when i changed my wordpress language to sv_SE the language in BBpress changed as well.
Do you have a deep integrated setup? If not then that can’t be the reason, both works independently
Yes i have deep integration and I haven’t tried it without so that might be the reason why it works for most people.
