object' does not contain a definition forValue' and no extension method
Value' of typeobject' could be found. Are you missing an assembly reference?"
The errors are all similar to this one. Some complain about no definition for .Key
I do not have more information because I freaked out and immediately reverted the project back to Spine 3.7. Knowing that this issue will occur, I'd be willing to update again to help find the issue.