DDEV is a Docker-based tool that provisions the web server, PHP and database for a local development environment in isolated containers. It is a good choice when you don't want to install PHP and Composer on your operating system. This article creates a new October CMS project with DDEV and opens it in the browser in a few commands.

The backend panel can display a "Page not found" (404) page during or after installing October CMS. If the application cannot find the database, the backend shows a 404 page.

A blank screen can be displayed when you open the application during or after installing October CMS.

Composer shows the error Invalid credentials (HTTP 403) for '...', aborting. when the auth.json file is missing on your server or your project license has expired.

An error "Unable to get local issuer certificate" can be displayed when installing October CMS. The complete error may read cURL error 60: SSL certificate problem: unable to get local issuer certificate.

The following guide can be used to install October CMS v4 atop an existing Laravel 12 application. This is useful if you want to keep the same database without losing data or just prefer to use Laravel as a starting point.

Laragon is a portable, isolated local development environment for Windows. It includes PHP, Apache, MySQL and Composer, and its Auto Virtual Hosts feature gives every project in its www folder a pretty URL such as http://myoctober.test. This article installs October CMS from Laragon's terminal, using Laragon's MySQL server and an automatic virtual host.

An error "Specified key was too long" can be displayed when running the database migration. This can happen with older versions of MySQL or MariaDB. The complete error may read SQLSTATE[42000]: Syntax error or access violation: 1071 Specified key was too long; max key length is 767 bytes.

Laravel Sail is a light-weight command-line interface for Laravel's default Docker development environment. Since October CMS is built on Laravel, Sail can be added to an October CMS project to run PHP and MySQL in Docker containers. This article creates a new project, adds Sail to it, and installs October CMS inside the containers.

An "Invalid security token" error can be displayed when logging in, during or after installing October CMS.

The October CMS installation can freeze after you enter the license key. This can happen in some environments when you paste the license key.