WooCommerce Stripe Gateway was updated to version 3.0.1, from version 2.6.9. Changelogs:
3.0.1
- Backwards compatibility update to prevent error finding WC_Payment_Token_CC.
- Added inline validation of keys.
3.0.0
- First public WordPress.org release.
- Refactor for WC 2.6 and above. Legacy support for 2.5.
- Improved saved card handling using tokenization API in WooCommerce.