Go to folder with modules, find captcha folder and remove (delete)
you can do this from ftp connection of file manager from cPanel. After you remove this module try to find compatible module version for your prestashop version.
or change or increase your php settings to new (be sure that your version of prestashop is supporting this php)
https://devdocs.prestashop.com/1.7/basics/installation/system-requirements/
For best software performance and stable work, please use recommended PHP version & settings
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Go to folder with modules, find captcha folder and remove (delete)
you can do this from ftp connection of file manager from cPanel. After you remove this module try to find compatible module version for your prestashop version.
or change or increase your php settings to new (be sure that your version of prestashop is supporting this php)
https://devdocs.prestashop.com/1.7/basics/installation/system-requirements/