PHP include Failed to Open Stream: Fix the File Path

include(): Failed to open stream, often followed by Failed opening required, does not necessarily mean the file was deleted. PHP may simply be resolving a different path from the one the application author had in mind. A relative path that works on a local Windows machine can fail after deployment to Linux.

Find the base PHP is using

A statement such as include 'config.php'; is resolved using PHP's include search behavior and the request's working context. The result can differ when the app is launched through another entry point, a cron job or a different working directory. Check the complete path in the server log; do not expose private filesystem paths in a visitor-facing error.

If a file should be resolved relative to the PHP file that references it, use __DIR__ as a stable base:

require_once __DIR__ . '/../app/bootstrap.php';

For controlled diagnostics, realpath() and is_readable() can help distinguish a missing path from a permissions problem. A required bootstrap should fail clearly; an optional feature can use a checked include and a deliberate fallback. Avoid building a path from an environment variable before confirming that the variable is defined and non-empty.

You can temporarily log getcwd() and get_include_path() to understand how PHP is searching. Remove or restrict that diagnostic afterward because the values may reveal the server's directory layout.

Check filename case and permissions on Linux

Some Windows development setups tolerate a case difference that Linux does not: Config.php and config.php are different filenames on a case-sensitive filesystem. Compare the name in the repository, the deployed file and the include statement character by character. If only the case changed, verify that Git recorded the rename and the deployment contains the expected commit.

For a permissions failure, check not only whether the file is readable but whether the PHP-FPM or web-server user can traverse each parent directory. Broadly opening permissions is not a safe fix; correct ownership and the minimum required access instead.

PHP describes the search behavior in its include reference; magic constants documents __DIR__. For a larger application, see multi-layer MVC architecture in PHP.