phtcloud Sorry for the confusion! The issue where projects with bad meshes cannot open in 4.3.39-beta is a known issue, and it has already been fixed in the unreleased 4.3.40-beta.
We checked the Spine project you sent, and it can be opened in 4.3.40-beta, so once that version is released, your projects should open as well. This patch version should be released soon!