I have made some test projects where I loaded a map, then created an avatar, and it worked. When the beta 5 was released, I created a new project, and I reused the avatar I created for the past projects, but I was unable to create an avatar instance, the openspace engine tells me :
[WARNING] An error occurred while creating avatar '1': Invalid main avatar class definition for 'girl' avatar type: class must extend Avatar
I can't understand why
Edit : the same is happening when I use the DemoAvatar contained in the flex example