I'm not sure when this is happening or what's causing it, but I've gotten this error a few times...
1x [ADDON_ACTION_BLOCKED] AddOn 'Chinchilla' tried to call the protected function 'ArenaEnemyFrames:ClearAllPoints()'.
!BugGrabber\BugGrabber.lua:519: in function <!BugGrabber\BugGrabber.lua:519>
[C]: in function ClearAllPoints' FrameXML\UIParent.lua:3080: in function UIParentManageFramePositions'
FrameXML\UIParent.lua:2329: in function <FrameXML\UIParent.lua:2316>
[C]: in function SetAttribute' FrameXML\UIParent.lua:3118: in function <FrameXML\UIParent.lua:3116> [C]: in function UIParent_ManageFramePositions'
FrameXML\TargetFrame.lua:182: in function `OnEvent'
FrameXML\UnitFrame.lua:926: in function <FrameXML\UnitFrame.lua:924>

Locals:
InCombatSkipped

Happened again when I targetted the first boss of a dungeon.

3x [ADDON_ACTION_BLOCKED] AddOn 'Chinchilla' tried to call the protected function 'ArenaEnemyFrames:ClearAllPoints()'.
!BugGrabber\BugGrabber.lua:519: in function <!BugGrabber\BugGrabber.lua:519>
[C]: in function ClearAllPoints' FrameXML\UIParent.lua:3080: in function UIParentManageFramePositions'
FrameXML\UIParent.lua:2329: in function <FrameXML\UIParent.lua:2316>
[C]: in function SetAttribute' FrameXML\UIParent.lua:3118: in function UIParent_ManageFramePositions'
FrameXML\BuffFrame.lua:331: in function BuffFrame_UpdateAllBuffAnchors' FrameXML\BuffFrame.lua:104: in function <FrameXML\BuffFrame.lua:87> [C]: ? [C]: in function BuffFrame_Update'
FrameXML\BuffFrame.lua:49: in function <FrameXML\BuffFrame.lua:45>

Locals:
InCombatSkipped

Chinchilla does not alter the arena or buff frames in any way. Something else is causing this issue.

That's what I kind of figured, but thought I'd drop the bugs here anyway. Over the next few days, I'll try to disable the addon and run a couple dungeons to see what happens and I'll get back to you.
Thanks for the response.

Disabled this addon and didn't get any errors. Re-enabled it, and the errors returned.

As far as the frames go, I've had to use MoveAnything to move the buff frames away from the Chinchilla minimap. I haven't done anything to arena frames. I've never even done a single arena. But that doesn't explain to me why I don't get the errors when I don't have Chinchilla enabled. What should I do next to troubleshoot the issue?

Chinchilla and MoveAnything have never behaved well together.

I would recommend either

1. Disable the Position, MoveButtons, and ShowHide modules in the Chinchilla config, reload the UI, and solely use MoveAnything, or
2. Disable MoveAnything.

Aww, that makes me sad!
Would you be willing to implement moving the buff and debuff frames with your addon? They're right next to the default location of the minimap (my preferred area for it too), and if we enlarge the map like we can with Chinchilla, Chinchilla doesn't automatically nudge them over. So everything starts overlapping and becomes a real mess. Then, MoveAnything wouldn't be necessary for that at least.
I use MoveAnything for a lot more than just the buff frames, so if I had to get rid of anything, it'd be Chinchilla, unfortunately. And I'd really REALLY like to keep Chinchilla! :(

I think I figured it out. It started happening after I used Chinchilla's moving options to move the boss frames. (The boss frames are way too small, by the way. Much smaller than the original frames.) Another addon that also moves the boss frames gets the same error. You'll see the error in the comments:
https://www.curseforge.com/wow/addons/simple-boss-frame

Also, does Chinchilla not offer a way to reset each individual option of whatever you've moved to it's original position?