In Spine 4.0.49, I am unable to create new transform constraints. If I select a bone and then click New > Transform Constraint, nothing happens; normally you would be prompted to select a bone to constrain to, but this never occurs.
My guess is it may be due to the number of bones and constraints I have. I've experienced bugs (see below) due to this in 3.8.xx, but the constraint bug is new to 4.0.xx.
(Second bug):
For some time, even in Spine 3.8.xx and previous (possibly back to 3.7.xx or before), the Metrics panel has not displayed any data. See screenshot - all metrics are "0". I have hundreds of bones and constraints, unsure of the exact number.
Spine file is attached.
char_OMNI_v139.spine