**Symfony version(s) affected**: 5.0 **Description** <!-- A clear and concise description of the problem. --> A preload file was generated at `var/cache/dev/srcApp_KernelDevDebugContainer.preload.php` but is now missing. **How to reproduce** <!-- Code and/or config needed to reproduce the problem. If it's a complex bug, create a "bug reproducer" as explained in: https://symfony.com/doc/current/contributing/code/reproducer.html --> Create a new website-skeleton app and check for the file. **Possible Solution** <!--- Optional: only if you have suggestions on a fix/reason for the bug --> **Additional context** <!-- Optional: any other context about the problem: log messages, screenshots, etc. -->