I am troubleshooting this issue currently on 2 separate Mautic test instances. Will edit and update as troubleshooting process yields a positive result.
Your software
My Mautic version is: 4.0.0-rc
My PHP version is: 7.4
My Database type and version is: MariaDb 10.5.11
Your problem
My problem is: After CLI update to 4.0.0-rc I get 500 error when clicking “Emails” under Channels menu
These errors are showing in the log: mautic.CRITICAL: Uncaught PHP Exception Mautic\CoreBundle\Exception\BadConfigurationException: “Theme Confirm Me not configured properly: builder property in the config.json” at /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/bundles/CoreBundle/Helper/ThemeHelper.php line 673 {“exception”:"[object] (Mautic\CoreBundle\Exception\BadConfigurationException(code: 0): Theme Confirm Me not configured properly: builder property in the config.json at /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/bundles/CoreBundle/Helper/ThemeHelper.php:673)
[stacktrace]
#0 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/bundles/CoreBundle/Helper/ThemeHelper.php(622): Mautic\CoreBundle\Helper\ThemeHelper->shouldLoadTheme()
#1 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/bundles/CoreBundle/Helper/ThemeHelper.php(347): Mautic\CoreBundle\Helper\ThemeHelper->loadThemes()
#2 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/bundles/CoreBundle/Factory/MauticFactory.php(337): Mautic\CoreBundle\Helper\ThemeHelper->getInstalledThemes()
#3 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/bundles/EmailBundle/Controller/EmailController.php(115): Mautic\CoreBundle\Factory\MauticFactory->getInstalledThemes()
#4 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/vendor/symfony/http-kernel/HttpKernel.php(158): Mautic\EmailBundle\Controller\EmailController->indexAction()
#5 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/vendor/symfony/http-kernel/HttpKernel.php(80): Symfony\Component\HttpKernel\HttpKernel->handleRaw()
#6 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/vendor/symfony/http-kernel/Kernel.php(201): Symfony\Component\HttpKernel\HttpKernel->handle()
#7 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/AppKernel.php(115): Symfony\Component\HttpKernel\Kernel->handle()
#8 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/middlewares/CORSMiddleware.php(91): AppKernel->handle()
#9 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/middlewares/CatchExceptionMiddleware.php(43): Mautic\Middleware\CORSMiddleware->handle()
#10 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/middlewares/VersionCheckMiddleware.php(67): Mautic\Middleware\CatchExceptionMiddleware->handle()
#11 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/app/middlewares/TrustMiddleware.php(51): Mautic\Middleware\VersionCheckMiddleware->handle()
#12 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Mautic\Middleware\TrustMiddleware->handle()
#13 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/vendor/stack/run/src/Stack/run.php(13): Stack\StackedHttpKernel->handle()
#14 /var/www/vhosts/Mautic-Install.com/app.Mautic-Install.com/index.php(24): Stack
un()
#15 {main}
Steps I have tried to fix the problem: Cleared cache, checked config.json in the listed theme. Found a format issue on line 5: “builder”: “grapesjsbuilder”, when it should be “builder”: [“grapesjsbuilder”],
Added brackets and saved config.json and the 500 error went away.