Craft CMS troubleshooting

# Common errors with initial setup

Most Craft CMS installation failures stem from four configuration issues. Resolve each of these to get your app running:

• Mismatching Security Key — Ensure the security key is identical between your local development environment and your fortrabbit environment.
• Wrong database configuration — Configure your app to use the ENV vars provided by the fortrabbit dashboard to connect to the database in production. Local .env files are ignored on fortrabbit. See ENV vars for setup details.
• Missing table prefix — If you use a table prefix locally (e.g., to run multiple Craft installations in one database), set the same prefix in production. Configure it via environment variable locally in .env, and on fortrabbit via the dashboard.
• Missing .htaccess file — This often occurs with SFTP uploads. Since .htaccess is a hidden file, ensure it is copied to your app root along with all other project files.

# Temporarily turning on/off dev mode

Production environments suppress error output to prevent information disclosure. When a runtime exception occurs, you will be presented with a generic "Service Unavailable" error screen. Temporarily enable dev mode to surface error details for debugging: set CRAFT_ENVIRONMENT to dev or toggle dev mode in the dashboard. Use this only on non-production environments.

# Large assets upload problems

Upload limits are typically controlled by Craft CMS's maxuploadfilesize setting or PHP's post_max_size, memory_limit, upload_max_filesize, and max_execution_time directives. These can be configured in the fortrabbit dashboard; check their current values if uploads fail. See the Craft CMS assets documentation↗ and review your app's logs to diagnose upload errors.