Here is a list of the components you are allowed on avatars

VRChat

• VRC_AvatarDescriptor
• VRC_IKFollower
• PipelineManager

Unity

• Transform
• Animator
• SkinnedMeshRenderer
• MeshFilter
• MeshRenderer
• Animation
• ParticleSystem
• ParticleSystemRenderer
• ParticleRenderer
• ParticleAnimator
• EllipsoidParticleEmitter
• MeshParticleEmitter
• TrailRenderer
• Cloth
• Light
• Collider
• Rigidbody
• Joint
• Camera*
• FlareLayer
• GUILayer
• AudioSource

DynamicBone

• DynamicBone
• DynamicBoneCollider

Root Motion

• VRIK**
• FullBodyBipedIK**

* Camera is only activated locally
** Using this script on a humanoid avatar will break it