eZ Platform Discussions

2.5.3 /admin/login produces error

Output from apaches error_log:

[Sat Aug 03 04:15:09.456593 2019] [php7:error] [pid 22396] [client 84.214.222.174:61989] PHP Fatal error: Uncaught Symfony\Component\Debug\Exception\FatalThrowableError: Call to a member function jsonSerialize() on null in /srv/www/enersen.no/docs/vendor/ocramius/proxy-manager/src/ProxyManager/GeneratorStrategy/EvaluatingGeneratorStrategy.php(70) : eval()'d code:72\nStack trace:\n#0 [internal function]: ProxyManagerGeneratedProxy\PM\EzSystems\EzPlatformAdminUi\UI\Config\ConfigWrapper\Generated89a3c2e40e24ac0f40bc043e24ec8ed2->jsonSerialize()\n#1 /srv/www/enersen.no/docs/var/cache/prod/twig/a9/a99c8926fa58607a2af994471e79b10126468040058c46af39ebcdc340f209cd.php(118): json_encode(Object(ProxyManagerGeneratedProxy\PM\EzSystems\EzPlatformAdminUi\UI\Config\ConfigWrapper\Generated89a3c2e40e24ac0f40bc043e24ec8ed2))\n#2 /srv/www/enersen.no/docs/vendor/twig/twig/src/Template.php(407): __TwigTemplate_f22d94e5fd17cd2f38ed1bf53ca20d4e2b16818b11e2384209d7685e0b05af5f->doDisplay(Array, Array)\n#3 /srv/www/enersen.no/docs/vendor/twig/twig/src/Template.php(380): Twig\Template->displayWithErrorHandling(Array, Array)\n#4 /srv/ww in /srv/www/enersen.no/docs/vendor/ocramius/proxy-manager/src/ProxyManager/GeneratorStrategy/EvaluatingGeneratorStrategy.php(70) : eval()'d code on line 72

Anyone?