Unable to edit or delete animation event added to imported animation

I have added a animation event to a animation that was imported from Maya, but i am unable to add any function to the Animation event or delete it. If i create a animation within unity it works just fine. Is this a bug, or am i just doing it wrong?

You should not be able to add an animation event to an imported animation. If you were able to do so, then that's a bug. In order to make it disappear again, you can re-import the animation.

For the supported way of adding animation events to imported animation resources, see the answer by straydogstrut, and further information here.

Although this is an old question, i'll copy in Dreamora's answer from a similar question here incase anyone ends up here.

animations imported with model assets are read only.

You can only edit animations you created from within unity.

This is to allow you to update your asset later on. If you could edit the animation curve, your chances would be killed directly again on your next update of the model from maya / asset reimport

As discussed in this post, if you want to edit an imported animation, you will need to copy it.