What do you mean by “Translated the all into a different language”
-> if by language you mean coding languages, I’m not sure how you would even go about doing this.
-> if you mean like a spoken language via the config of a plugin, which plugin was this, or which plugins did you change. It could be outdated or broken.
Your server (if you mean by world and all data-including plugins-) was reset, it could have only been due to you hitting the reset server button, or if something terribly wrong happened which caused the server to reset, the later not likely.