English strings in 4.0.1 nl_NL (and possibly other languages too)

In the nl_NL Support forumSupport Forum WordPress Support Forums is a place to go for help and conversations around using WordPress. Also the place to go to report issues that are caused by errors with the WordPress code and implementations. https://en.forums.wordpress.com/. some users reported that there were some English stringsString A string is a translatable part of the software. A translation consists of a multitude of localized strings. in the nl_NL version. So I tested this and confirmed that the Add Media an Featured imange strings (and maybe others) were not translated. I discussed with my Dutch translations colleagues and Remkus said that he would build a new package for 4.0.1. After whcih I reinstalled, but the strings were still in English.

Then I saw a tweet of @pixolin where he stated that the same problem occurs/occured in the de_DE version of 4.0.1. His tip was to Update Translations in the Update screen. But, this was not available. Even after removing the po/mo filesMO files MO, or Machine Object is a binary data file that contains object data referenced by a program. It is typically used to translate program code, and may be loaded or imported into the GNU gettext program. This is the format used in a WordPress install. These files are normally located inside .../wp-content/languages/ in the /wp-content/languages directory.

Here’s what I did to solve this:

  • Set language to English in Settings -> General
  • Remove po/mo files in the /wp-content/languages directory
  • Add define( ‘WPLANG ‘ , ‘nl_NL’ ); in wp-config.php (otherwise this cannot be selected in Settings -> General
  • Set language to Dutch (Nederlands) in Settings -> General
  • Remove WPLANG from wp-config.php
  • Go to Dashboard -> Updates and click “Update Translation”

So, what went wrong here, and how can we avoid this from happening next time?