Basically fresh install of Magento 2.2.5. Whenever I switch to developer mode, my site completely breaks with:

ReflectionException: Class Magento\Framework\App\Http\Interceptor does not exist in /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/vendor/magento/framework/Code/Reader/ClassReader.php:19 Stack trace: #0 /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/vendor/magento/framework/Code/Reader/ClassReader.php(19): ReflectionClass->__construct('Magento\\Framewo...') #1 /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/vendor/magento/framework/ObjectManager/Definition/Runtime.php(44): Magento\Framework\Code\Reader\ClassReader->getConstructor('Magento\\Framewo...') #2 /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/vendor/magento/framework/ObjectManager/Factory/Dynamic/Developer.php(48): Magento\Framework\ObjectManager\Definition\Runtime->getParameters('Magento\\Framewo...') #3 /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/vendor/magento/framework/ObjectManager/ObjectManager.php(56): Magento\Framework\ObjectManager\Factory\Dynamic\Developer->create('Magento\\Framewo...', Array) #4 /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/vendor/magento/framework/App/Bootstrap.php(232): Magento\Framework\ObjectManager\ObjectManager->create('Magento\\Framewo...', Array) #5 /home/200582.cloudwaysapps.com/dyxjcgvyzs/public_html/pub/index.php(36): Magento\Framework\App\Bootstrap->createApplication('Magento\\Framewo...') #6 {main}

After this, I do all kinds of things like resetting permissions, clearing cache, switching back and forth from production to developer, rm -rf var/cache/* var/page_cache/* var/generation/* and find var generated pub/static pub/media app/etc -type f -exec chmod g+w {} \; && find var generated pub/static pub/media app/etc -type d -exec chmod g+ws {} \;, restarting services, and so on. I cannot find a pattern or cause for what is going on. Sometimes I clear the cache, and it comes back. Sometimes I reset permissions, and it works. But sometimes not. But switching to developer mode always breaks it.


1 Answer 1


Turns out this had to do with missing classes that was caused by me running this recommended Magento optimization:

composer dump-autoload -o --apcu

To revert this, I first tried deleting the vendor/composer directory completely, doing composer update, and magento setup:upgrade. This might help others, but I am not 100% sure b/c I then ran into unrelated redirect issues - but I no longer received the ReflectionException error.

When I restored to a backup before doing the dump-autoload, this fixed my Magento 2 install, and I checked the vendor/composer directory to be sure the autoloader files there were the ones installed by default.

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