I loaded some animations onto a character via Mixamo, having used their autorigger as well. When I import the FBX into UE4 it claims that there is no bind pose. Would this be a problem, or could I just ignore it?
A bind pose is the position of the model when you bound it to the rig. Move the rig the model is no longer in the position that it was bound to. In general FBX complains a lot about things that are not critical and the bind pose is one of them. The worst I can see happening is if the skin weighting is turned off the model will snap to it’s position prior to skin weighting being added.
Generally I ignore it.