Error 500 in POST of tapatalk /mibiquo/mobiquo.php

  • Hello everyone:

    I use the following:
    Debian strech
    i-MSCP 1.5.1 Build: 20170908
    PHP 7.1.12-1 + 0 ~ 20171129100550.11 + stretch ~ 1.gbp8ded15

    I have moved a site using Joomla and the tapatalk forum to my server.
    I find something in the apache2 log of the site that brings me a little clueless.

    "POST /mobiquo/mobiquo.php HTTP / 1.1" 500 870

    The rest of the sites and this included, everything works correctly.

    I have uninstalled the tapatalk plugin and the app, and reinstalled it with the same fresh latest version.

    The permissions directories from /mobiquo are 755 and files 644 with the correct user and group owner of the site, vu2020.vu2020 in this case.

    In the php log there is no clue, (cat /var/log/php7.1-fpm.log). In the error log of apache in the virtualhost either, only in the file access.log what I have put above.

    Could someone please give me a clue as to where to find the way to solve this problem?

    Many thanks in advance to this great team.