error with exporting poses on Mac

Hello, 

Is someone able to guide me with this error am getting when exporting a pose from a mac?

thank you 




Sims 4 Studio 1.3.4.2 (Apple Blossom)
S4Studio.Blender.BlenderException:
File "/Users/[UserName]/.local/share/S4Studio/Scripts/clipimporter.py", line 44, in <module>
load_clip(clip,rig)
File "/Users/[UserName]/Library/Application Support/Blender/2.78/scripts/addons/s4studio/animation/blender.py", line 139, in load_clip
animate_bone(skeleton.pose.bones[ROOT_BONE])
KeyError: 'bpy_prop_collection[key]: key "b__ROOT__" not found'


at S4Studio.Blender.BlenderUtilities.RunBlender (System.String script, System.String blend, System.Boolean background, System.Boolean check_version) [0x00313] in <6f064ec3ebe048448397ea60b2ecded2>:0
at S4Studio.Blender.BlenderUtilities.ExportClip (System.String custom_blend, System.String custom_clip, System.String mannequin_folder, System.String mannequin_texture, System.String rig_resource) [0x000f4] in <6f064ec3ebe048448397ea60b2ecded2>:0
at S4Studio.ViewModels.Animation.AnimationPackCustomContent+<>c__DisplayClass152_0.<DoExport>b__0 () [0x00107] in <6f064ec3ebe048448397ea60b2ecded2>:0
at S4S.UI.Core.S4SWindow+<>c__DisplayClass11_0.<BeginLoading>b__1 () [0x00014] in <6f064ec3ebe048448397ea60b2ecded2>:0