Spine Extension updated from Spine 4.0 to Spine 4.1 which means all the Spine models in your project should be re-exported to be able to use the newest 2.10.0 version of the extension.
This version supports sequences (Frame-by-frame animations) and is compatible with Defold 1.4.4+.
You can migrate your project when it’s comfortable for you, until then use Defold Spine Extension 2.9.1 which is also compatible with Defold 1.4.4+.
If you use Defold 1.4.3, then stay on an older version of the extension, e.g. 2.7.1 (see releases)