Hi Nikita,
Yes, it is by design that the Spine editor version that you export from needs to match the Spine runtime version that you use. Occassionally, data from an older editor version will work with a newer runtime, but we can't guarantee this.
In general, loading your old Spine models into the new editor version and re-exporting should do the trick. Alternatively, you can stay at the old editor/runtime version if you don't need features of the latest Spine version.
Cheers,
Mario
