Bug found when change mode.

[downtiser]

When I fist enter the raspberryPi mode and enter the ip address, the mode functions as expected, but when I change to Python mode, then change back to raspberryPi mode, there is an error in the browser console: Unhandled rejection TypeError: Cannot read property 'parentElement' of undefined at Object.exports.proposeGeometry (http://app.edublocks.org/lib/xterm.js/addons/fit/fit.js:35:23) at Object.exports.fit (http://app.edublocks.org/lib/xterm.js/addons/fit/fit.js:70:28) at Terminal.Xterm.fit (http://app.edublocks.org/lib/xterm.js/addons/fit/fit.js:82:20) at RemoteShellView.fit (http://app.edublocks.org/dist/main.js:18818:19) at RemoteShellView.componentDidUpdate (http://app.edublocks.org/dist/main.js:18842:14) at renderComponent (http://app.edublocks.org/dist/main.js:87160:61) at setComponentProps (http://app.edublocks.org/dist/main.js:87092:115) at buildComponentFromVNode (http://app.edublocks.org/dist/main.js:87171:13) at idiff (http://app.edublocks.org/dist/main.js:86978:52) at innerDiffNode (http://app.edublocks.org/dist/main.js:87027:21) at idiff (http://app.edublocks.org/dist/main.js:86996:65) at diff (http://app.edublocks.org/dist/main.js:86953:19) at renderComponent (http://app.edublocks.org/dist/main.js:87137:32) at rerender (http://app.edublocks.org/dist/main.js:86883:44) at r (https://cdnjs.cloudflare.com/ajax/libs/bluebird/3.3.5/bluebird.min.js:31:7444) at r._settlePromiseFromHandler (https://cdnjs.cloudflare.com/ajax/libs/bluebird/3.3.5/bluebird.min.js:30:12758) and I fail to open the Extra modal and sample modal, the terminal also can't be opened when I click Run button.