Polylang 500 internal Error

Hello everyone and thanks for your help (sorry for my english, im french)
I’m using WP 5.7, with Jupiter X 1.20.1 and Polylang 3.0.2, and i was working on a futur Spain version when the website crashs : 500 internal error.
i begun to desactivate all plugins, website came back.
I try to reactivate all plugins >> crash
i try to reactivate all plugin without Polylang >> works.

I try to desactivate all plugin, then activate only Polylang >> Works.
I add only Jupitex X >> Crash

I try to come back to WP 5.6.2 >> same issue
i try to come bakc to wp 5.6.2 + Polylang 2.9.1 >> same issue

i try to activate debug.log >> doesn’t work because my server is on IONOS, the the log file is on the root… i found and read de log file :

91.166.193.0 - - [20/Mar/2021:01:35:07 +0100] "GET /wp-admin/plugins.php?action=activate&plugin=polylang%2Fpolylang.php&plugin_status=all&paged=1&s&_wpnonce=ad2bc36f60 HTTP/1.1" 302 - s848113647.onlinehome.fr "https://s848113647.onlinehome.fr/wp-admin/plugins.php" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0" "-"
91.166.193.0 - - [20/Mar/2021:01:35:07 +0100] "GET /wp-admin/plugins.php?activate=true&plugin_status=all&paged=1&s= HTTP/1.1" 500 669 s848113647.onlinehome.fr "https://s848113647.onlinehome.fr/wp-admin/plugins.php" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0" "-"
91.166.193.0 - - [20/Mar/2021:01:35:17 +0100] "GET /favicon.ico HTTP/1.1" 200 8895 s848113647.onlinehome.fr "https://s848113647.onlinehome.fr/wp-admin/plugins.php?activate=true&plugin_status=all&paged=1&s=" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0" "-"
91.166.193.0 - - [20/Mar/2021:01:36:22 +0100] "POST /wp-admin/admin-ajax.php HTTP/1.1" 500 669 s848113647.onlinehome.fr "https://s848113647.onlinehome.fr/wp-admin/post.php?post=2893&action=elementor" "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0" "-"

i’ve no more ideas to test… Thanks for your help !

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