Recieving error message when trying to export to blender

Whenever I try to export my rig with a gun to blender I’m getting this error message in the blender export/import plugin.
(cloud_16708835782.BlenderAnimations.Components.RigPart:111: Joint connecting Part to Cartridge not found)
I’ve already rerigged the model many times and downloaded the current version but I’m still recieving the same error