avatar can't sit in chair or sofa etc.

[RenkaFairywren]

The sitting motion does not work.

I select the sit motion and sit down, but the sit animation does not work.

[Lindal Kidd]

This can happen if the owner of the item you are trying to sit on has restricted its use to a specific group of people.

Also, you may be wearing an animation with a higher priority than the sit animation in the object. Turn off or remove any animation overrider you're wearing, and check for animations in other things, for example your shoes.

If you are trying to sit on a big flat object (such as a floor), it might not have a sit target in it.

[RenkaFairywren]

Make sure there is no animation worn, but can't sit down.