Bones roll after export when joining them to different armature

[Absalom96]

I extensively looked for this issue to check if it has been already posted, but apparently I’m the first one to experience this. Basically if I join the bones from an hand model to a different body model and then I export the model and import it again , the bones are all misaligned (apparently rotated).

[Candoran2]

Could you post the files and steps needed to reproduce this?

[HENDRIX-ZT2]

Not really a bug, but a feature, as the 'best' bone orientation is chosen for and stored on each armature. Joining armatures with different orientations is not possible for now.