This thread is resolved. Here is a description of the problem and solution.
Problem:Question about URL format
Solution:This message you are seeing can often be a "false negative" , meaning that even though you are seeing this warning the site is still working as expected.
language in directories URL structure will not work on a site that has WP installed in a subdirectory, and best way to test if the language in directories is working as expected is by visiting the front end.
if you are not getting a 404, blank screen or 403 error then you can move forward and ignore this warning
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