Failed Ajax request or invalid JSON returned error

I have this error every time i want to add a new user

Screen Shot 2021-02-16 at 2.35.08 PM

I’ve already reinstalled it and its the same
What can I do

Hello, could you please check your PHP logs for any errors? The errors there would hopefully provide us with more information about what’s going wrong.

[16-Feb-2021 20:11:59 UTC] PHP Fatal error: Uncaught Error: Call to undefined function bindtextdomain() in /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/AbstractDatabase.php:87
Stack trace:
#0 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/AbstractDatabase.php(46): Sokil\IsoCodes\AbstractDatabase->bindGettextDomain()
#1 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/IsoCodesFactory.php(65): Sokil\IsoCodes\AbstractDatabase->__construct(NULL)
#2 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/controllers/grid/settings/user/form/UserDetailsForm.inc.php(163): Sokil\IsoCodes\IsoCodesFactory->getCountries()
#3 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/controllers/grid/settings/user/UserGridHandler.inc.php(287): UserDetailsForm->display(Object(Request))
#4 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/controllers/grid/settings/user/UserGridHandler.inc.php(264): UserGridHandler->editUser(Array, in /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/AbstractDatabase.php on line 87
[16-Feb-2021 20:12:09 UTC] PHP Fatal error: Uncaught Error: Call to undefined function bindtextdomain() in /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/AbstractDatabase.php:87
Stack trace:
#0 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/AbstractDatabase.php(46): Sokil\IsoCodes\AbstractDatabase->bindGettextDomain()
#1 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/IsoCodesFactory.php(65): Sokil\IsoCodes\AbstractDatabase->__construct(NULL)
#2 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/controllers/grid/settings/user/form/UserDetailsForm.inc.php(163): Sokil\IsoCodes\IsoCodesFactory->getCountries()
#3 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/controllers/grid/settings/user/UserGridHandler.inc.php(287): UserDetailsForm->display(Object(Request))
#4 /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/controllers/grid/settings/user/UserGridHandler.inc.php(264): UserGridHandler->editUser(Array, in /home/biofabco/public_html/tecnohumanismo.online/lib/pkp/lib/vendor/sokil/php-isocodes/src/AbstractDatabase.php on line 87

maybe this post could help to solve the problem, at least the one that is reported in the PHP logs: