On Tuesday 19 March 2019, lang.moodle.org unfortunately experienced a server crash and our system administrators had to restore the site's moodledata from a backup. All data restored fine to our knowledge, with the exception of 6 translation contributions, as listed in MDLSITE-5698.
We apologise for the data loss and for the inconvenience caused. I will be contacting the 6 contributors individually to request for them to resubmit their translations.