Uncaught RangeError upon deleting a rich text cell

[KevinDCarlson]

Workflow: make a rich text cell, then delete it. The following prints to console:

Uncaught RangeError: Cannot splice: RangeError: invalid object id: invalid path _root/notebook/cells/0/content: path component 2 (0) referenced a nonexistent object
    at xa (index-DKwPyY2I.js:3:44554)
    at sX (index-DKwPyY2I.js:30:36737)
    at c3.o (index-DKwPyY2I.js:30:42747)
    at a.emit (index-DKwPyY2I.js:3:54093)
    at c3.KR (index-DKwPyY2I.js:5:49491)
    at index-DKwPyY2I.js:5:47242
    at Dj.update (index-DKwPyY2I.js:3:62046)
    at Dj._process (index-DKwPyY2I.js:3:64138)
    at Eb.flush (index-DKwPyY2I.js:3:55819)
    at Eb.enqueue (index-DKwPyY2I.js:3:55755)

I've checked this in a couple of theories. Just on Chrome in OS X, but I think it's probably in our code.

[epatters]

Sigh. I thought this was fixed. I've seen stuff like this before. It has to do with automerge-prosemirror.