Animation Editor Won't Open

[Chrythm]

I can’t open the animation editor. Upon opening a new studio and inserting my rig, the animation editor will open, freeze, and I will no longer be able to open in. Errors show up in the console:

This happens every time in every studio (with most rigs). All I did was open the editor with the model selected.
rat.rbxm (52.3 KB)
Here’s the rig I used. If it’s a rig problem, tell me what’s wrong with the rig.

This just started happening yesterday. Before that day, all was working fine as far as I know.

[Legoracer (xyz)]

Restarting your studio and/or updating Animation editor should fix it for you if it ever occurs.
Would be good if Roblox fixed it permanently though.

[Chrythm]

Neither of these had an effect. This happens in every game studio, even a baseplate.

[JollySunbro6]

Thank you for providing the rig you are having issues with. I will start investigating the cause now

Edit: Please unanchor all the parts in your rig aside from the HumanoidRootPart. It seems that when a part becomes anchored, the part itself is considered the root from GetRootPart(), this causes some confusion in the animation editor and is the source of the errors. We will try to get additional warnings of this case in there to prevent this from happening again

[Chrythm]

That’s very odd, because I unanchored everything but the root when I saved the rig?

[Chrythm]

I’m no longer having this problem anymore.

Thank you for the help

[DarkBegin]

this reply is not the solution, click on the message of greywolf_sir who found the solution

[Chrythm]

I must’ve accidentally clicked the checkbox, I don’t remember clicking mine. I’ll fix it.

[Chrythm]

Now there’s another problem: When I lock stuff in the animation editor (this icon) it doesn’t save to the animation and the locked part stays locked when loading and reopening. I would prefer not to create another bug report because this is the whole bug, happens on every rig.