ERROR MESSAGE (LanguageCode) WHEN DATA DOWNLOAD

Hi,
I’ve been collecting data for a week now. I’ve already been able to download the first submitted data without any problem. But to my great surprise, this evening I want to upload the database again, but an error message appears as in the image below. What do I do now? I have two collection projects with the same problem at the moment. I’ve tried exporting with the old XLS version but the content is unusable.
What can I do to download the data in the excel format normally used with labels?
Thanks for your help.

@MMM_MINTOGBE, would you mind validating your XLSForm through this online validator to see if there are any syntax issues? There could also be data downloading issues when you have syntax issues within your XLSForm.