the described procedure ZCS 6.0:Zimbra REST API Reference:Import Contacts - Zimbra :: Wiki does not work for me.

When I try:
curl -USER:PASS--upload-file /var/share/result.csv https://SERVER/home/USER/FOLDER?fmt=csv
I get:
Warning: Invalid character is found in given range. A specified range MUST
Warning: have only digits in 'start'-'stop'. The server's response to this
Warning: request is uncertain.

When I try the -u command (as documented in curl --help), I get no warnings, no display of anything and nothing imported.

curl -u USER:PASS--upload-file /var/share/result.csv https://SERVER/home/USER/FOLDER?fmt=csv
USER, PASS, SERVER and FOLDER are of course my settings.

When I do I get an "empty" csv file (because no contacts have been imported yet).