Getting Error 500 Authorising OAuth2 from Joomla

Your software
My Mautic version is: v2.15.3
My PHP version is: 7.2
My Joomla version is: 3.9.14
My Mautic-Joomla Plugin version is: 1.0.0

Your problem
My problem is:
I’m getting the following Error trying to Authorise from the Joomla Plugin:
Error: The site is currently offline due to encountering an error. If the problem persists, please contact the system administrator. System administrators, check server logs for errors code:500

These errors are showing in the log:

2019-12-29 13:32:02 Error 185.166.214.127 500 POST /oauth/v2/token HTTP/1.0 Desconocido 1.45 K Acceso SSL/TLS a Apache
2019-12-29 13:32:02 Warning 185.166.214.127 AH01071: Got error ‘PHP message: PHP Warning: require(/var/www/vhosts/heading2market.com/mautic/app/cache/prod/doctrine/orm/Proxies/__CG__MauticUserBundleEntityUser.php): failed to open stream: No such file or directory in /var/www/vhosts/heading2market.com/mautic/vendor/doctrine/common/lib/Doctrine/Common/Proxy/AbstractProxyFactory.php on line 209\nPHP message: PHP Warning: require(/var/www/vhosts/heading2market.com/mautic/app/cache/prod/doctrine/orm/Proxies/__CG__MauticUserBundleEntityUser.php): failed to open stream: No such file or directory in /var/www/vhosts/heading2market.com/mautic/vendor/doctrine/common/lib/Doctrine/Common/Proxy/AbstractProxyFactory.php on line 209\nPHP message: PHP Fatal error: require(): Failed opening required ‘/var/www/vhosts/heading2market.com/mautic/app/cache/prod/doctrine/orm/Proxies/__CG__MauticUserBundleEntityUser.php’ (include_path=’.:/opt/plesk/php/7.2/share/pear’) in /var/www/vhosts/heading2market.com/mautic/vendor/doctrine/common/lib/Doctrine/Common/Proxy/AbstractProxyFactory.php on line 209\n’ Error de Apache

Steps I have tried to fix the problem:
None, I’ve no idea how to solve it

Well, I did a fresh install and solved

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