To reproduce:

• Open http://beta.musicbrainz.org/recording/b76bb83a-3fca-4911-b9e2-148432d9e25c/edit
• Click the edit icon for the karaoke version relationship
• Click "Change direction"
• Click "Done"

Expected behaviour: The dialog closes.
Actual behaviour: An error is produced (see below) and a second click is needed to close the dialog.

Uncaught exception: TypeError: Cannot convert '$parent.values.peek()[0]' to object

Error thrown at line 1, column 101 in <anonymous function: text>():
return MB.text.AddAnotherEntity[$parent.values.peek()[0].target($data).entityType]
called from line 11811, column 5 in <anonymous function: update>(t, e) in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
m.utils.setTextContent(t, e())
called from line 11403, column 9 in <anonymous function>() in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
s(t, y(a), r, o.$data, o)
called from line 10711, column 8 in a() in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
var s = i ? v.call : v()
called from line 10689, column 5 in r() in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
t && t >= 0 ? (clearTimeout(E), E = setTimeout(a, t)) : l._evalRateLimited ? l._evalRateLimited() : a()
called from line 10442, column 9 in <anonymous function: notifySubscribers>(t, e) in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
i.isDisposed || i.callback(t)
called from line 10529, column 5 in <anonymous function: i.valueHasMutated>() in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
i.notifySubscribers
called from line 10523, column 5 in i() in http://nikki.mbsandbox.org/static/build/common-bcc3d93e.js:
return arguments.length > 0 ? (i.isDifferent(n, arguments[0]) && (i.valueWillMutate(), n = arguments[0], t && (i._latestValue = n), i.valueHasMutated()), this) : (m.dependencyDetection.registerDependency, n)
called from line 698, column 3 in <anonymous function: fromJS>(e) in http://nikki.mbsandbox.org/static/build/edit-08125cbf.js:
this.linkTypeID(e.linkTypeID), this.entities([MB.entity(e.entities[0]), MB.entity(e.entities[1])]), n(this.period.beginDate, e.beginDate || {}), n(this.period.endDate, e.endDate || {}), this.period.ended(!!e.ended), this.setAttributes(e.attributes), this.linkOrder(e.linkOrder || 0), _.has(e, "removed") && this.removed(!!e.removed)
called from line 1361, column 3 in <anonymous function: augment$accept>() in http://nikki.mbsandbox.org/static/build/edit-08125cbf.js:
this.editing.fromJS(i.editData()), e.length && t(this.source, e)