Hi!
I encountered a really strange thing. When i select all bones in the pose mode and try to clear their transforms, it doesn’t do it, so I can’t reset the rig to the rest position:
Does anyone know why??
I got this problem seemingly after using the addon Animation Layers.
It does clear the transforms. After which, constraints (and possibly drivers) transform it, even if you don’t do anything.
Last time I looked at Rigify, which this looks like, it’d give you a stable rest pose-- constraint parameters would be automatically tuned such that your constraints wouldn’t have any rest pose effect. If you’ve edited the rig at all, like changed the positions or lengths of any bones, you should be changing those on the meta-rig instead, and then regenerating the rig.
In order to check certain amounts of unwilling Transformations and where they might be coming from: on Pose Mode from the Properties Editor, you can try to Hide each one of the Bone Constraints from the Bones in the Armature; so that you temporarily disable at least this whole category of Transformations from the Pose Position (Skeleton Panel < Object Data Properties Tab for the Armature Object). Just don’t forget later to Unhide the Bone Constraints.
To improve checking in a comparative way, you can also keep toggling between Pose|Edit Modes on the Armature Object, and, most radically: toggling between Pose Position and Rest Position on the Skeleton Panel.