Translations disappeared

file was all translated before. Few days ago we updated that file and after that all translated parts was disappeared

looks like you either changed the keys or file that was used for the update did not have previously uploaded keys to Crowdn

Yes, source string key should be always the same. In case, key is changed, the string will be recognized as new
Even if the text for translation is the same

Also, all translations are saved in Translation Memory. I believe, you can run pre-translate ™ to add these translations one more time