Hi Denis!
As we can see, the same request was sent to support@crowdin.com. We’ll need some more information, so will continue the conversation there
However, main notice is that API v1 version is almost deprecated and we’d strongly recommend migrating to API v2 version:
https://developer.crowdin.com/api/v2/
As well, please check if the exported translated file is well-looking or it’s the same as on the screenshot
Our tools call /update-file, then /pre-translate, then /export-file. The code on our side did not change, but since yesterday, the files we get from /export-file now contain malformed keys like you see on the screenshot. I’m guessing one of these endpoints is now doing something wrong 
Dear Denis, just got an update from the team that it’s not expected, in UI it also happens (it’s not API related thing) and we’ve created the task to fix that
Please accept our sincere apologies for the inconvenience
We seem to also hit the same issue. Uploaded strings from today have lost Unicode characters.
Dear @geokrety we’re sorry for that, however, our tech team is working on the fix and that will be deployed tomorrow in the morning, so then everything is supposed to look good again
Thanks @NataliaM. I had to revert the uploaded files from tomorrow and launch our CI job again. I can confirm this issue is gone.
Thanks [kumy from GeoKrety team]