when I edit "Look At" filed in "Camera Controls" folder, it report error

[wangzhengquan]

when I edit "Look At" filed in "Camera Controls" folder, it report the following error in the console:

mathquill.min.js:10 Uncaught Error: prayer failed: nodeId is the id of some Node that exists
    at s (mathquill.min.js:10:415)
    at t.seek (mathquill.min.js:10:27929)
    at HTMLSpanElement.<anonymous> (mathquill.min.js:10:27613)
    at HTMLSpanElement.dispatch (jquery-2.2.0.min.js:3:7519)
    at r.handle (jquery-2.2.0.min.js:3:5600)