To upgrade from really out-of-date versions of Subscriptions & WooCommerce is hard. WooCommerce often breaks backward compatibility, meaning you need to juggle versions.

Below is an upgrade path to go from Subscriptions version 1.4.2 and WooCommerce 2.0.n to WooCommerce 3.0.n and Subscriptions 2.2.n.

  1. Subscriptions 1.4.2 -> 1.4.7 (full compatibility with WC 2.1)
  2. WooCommerce 2.0.x -> 2.1.12
  3. Subscriptions 1.4.7 -> 1.5.10 (full compatibility with WC 2.2)
  4. WooCommerce 2.1.12 -> 2.2.11
  5. Subscriptions 1.5.15 -> 1.5.19 (full compatibility with WC 2.3)
  6. WooCommerce 2.2.11 -> 2.3.13
  7. Subscriptions 1.5.19 -> 1.5.29 (full compatibility with WC 2.3)
  8. WooCommerce 2.3.13 -> 2.4.13
  9. Subscriptions 1.5.29 -> 2.0.9 (full compatibility with WC 2.5)
  10. WooCommerce 2.4.13 -> 2.5.5
  11. Subscriptions 2.0.9 -> 2.0.15 (full compatibility with WC 2.6)
  12. WooCommerce 2.5.5 -> 2.6.14
  13. Subscriptions 2.0.15 -> 2.2.4 (full compatibility with WC 3.0)
  14. WooCommerce 2.6.14 -> 3.0.3