Hello @mefistofele82,
I wonder if this has to do with the line endings of the file. It looks like your file is using Windows line endings (CRLF), but Qiime and other linux software expect Linux line endings (LF).
I've converted your file so it's in the proper LF format. Let me know if this new file works.
Sample_metadataQIIME2_sheep_project_2017_2018-fixed.txt (54.1 KB)
Colin