Hi Robert,

we decided today not to use the second board. Instead of deleting it immediately, I deactivated it first - and what happens: The translations in the first board are suddenly correct again, just as we entered them in the translation tables.

When I activate the board again, the wrong phrases are displayed again. When I deactivate it again, they are correct again and so on. This can't really be up to us now ...

If you want to have a look at this phenomenon yourself: I haven't deleted the board for now, let me know and I'll enable your support access again.

Thank you, Bernd

Correct, this is what I did, and it worked perfect. I used Loco only now for looking at the files, when the problem occurred, but not changing them with Loco. 

I took a look at the new board we are working on. Here, these translations are correct as they had been in the "old" board – where the German terms are replaced by the English terms. Looking at the translations with the wpForo Phrase System from the dashboard of the new board it seems that not any string has been translated (what I did not do until now anyway). 

If needed, I can activate the old access to our backend. Thanks again for caring!

Bernd

Have you used the PO/MO files to translate? What kind of translation you have sued. I assume you've only used the wpForo Phrase System in Dashboard > wpForo > Phrases admin page.

If so, each board creates its own phrase pack and you may need to migrate the translated phrase to new board as well. It's really hard to debug your issue by discussing here, so we may need to see the database tables to understand what's going on (if the translation was made using the phrase system not the po/mo files).

In any case I recommend install Loco Translate plugin and create a new translation file in an update-safe folder.

Does not look professionell.

Sorry, I don't understand

Example
You can add the English word "Day" using the button and translate it to "Tag" (German)

What is unprofessional about it?

I did not use anything like Loco Translate etc. ever. Only during this conversation I had – for the first time – a look at the translation files with loco translate, without changing or saving anything. 

Looking at the pot-File with Loco does not show the problematic words either, like the translation tool inside WPForo does not. 

This is not wpForo problem so it may take even month to solve if you still use incorrect way to translate. First you should make sure the translation files are stored in update safe place. After installing wpForo and Logo translate plugin you should create/edit the language you want and copy the translation file to logo folder or to WordPress translation folder. 

Logo Translate plugin lets you copy the new language file to appropriate directories. The PM/MO files should be located in /wp-content/languages/plugins/ directory or in /wp-content/languages/loco/plugins/. Please make sure the po/mo files have wpforo- prefix, without this prefix they’ll not be processed.

If you don't keep them in a safe directory they will be removed and updated from wordpress.org with old ones and you'll have to translate them again.

But the single word "hour" or "hours" neither show up in the translation-tool of WPForo nor in Loco Translate. Nor does "day" oder "days" as a single word.

and that doesn't work for you either?

If you didn't find some phrase you can add it as well. just use the button.