Fix Magento/PHP error: AH01071: Got error 'PHP message: PHP Warning: Undefined array key "frontend" in vendor/magento/framework/ App/Cache/Frontend/Pool.php on line 90
Everything is running smoothly, and suddenly, you get a 500 error on your Magento storefront. First, check your PHP error logs.
If you have the following error:
AH01071: Got error 'PHP message: PHP Warning: Undefined array key "frontend" in vendor/magento/framework/App/Cache/Frontend/Pool.php on line 90
Then open your app/etc/env.php file. Look for the following lines:
'cache' => [
'graphql' => [
'id_salt' => 'RANDOM HASH HERE'
]
]
Comment out these lines and flush your cache. You may need to flush the cache by manually flushing Redis or var/cache since bin/magento c:f isn't going to work.
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