I think the solution is on this forum:
https://www.commentcamarche.net/forum/affich-12789160-probleme-wordpress # newanswer
For our tests, we never encountered this kind of problem, I think it is a problem in the encoding types.
Go to your wordpress directory -> wp-content -> plugins -> StudyPress. some place to Study-Press.php.par editor Notepad + +, in the “Encoding” menu, select ANSI.
