Hi,

Upgrading directly from Odoo Community v18 to v19 without starting fresh isn’t possible because Odoo doesn’t provide an in-place upgrade path for Community editions. Database structures change significantly between major versions, so simply pointing Odoo 19 to your v18 database would break the system.

If you want a seamless upgrade, the only official option is to switch to Enterprise, where Odoo’s upgrade service will migrate your database for you. For Community users, the most common approach is using OpenUpgrade, a community project that provides migration scripts to transform your v18 database into v19 format. However, this requires some technical setup and may need manual fixes for custom modules.

Another alternative is to do a clean install of Odoo 19 and manually export/import your important data such as customers, products, and invoices. This approach is simpler but you risk losing configuration and history unless carefully managed.

On Windows, migrations are harder since OpenUpgrade and Odoo are better supported on Linux. In practice, you may need a Linux VM, Docker, or WSL to run the migration, even if your production environment stays on Windows.

Hope it helps