JavaScript error with new Neos UI

[DavidSporer]

Hi,

first of all thank you for that package :-)
I'm using it and it's working really well. I've now tried to use it with the new UI and get a JavaScript error as soon as one of the Code Block node types has been added to the page.
I'm sorry that I'm not providing a pull request but maybe you can give me a hint where to look at.
The error I see is this one:

Uncaught TypeError: Cannot set property '/sites/support@user-davidsporer' of undefined
at t.value (Host.js:47)
at HTMLDivElement. (Host.js:41)
at Object._renderSubtreeIntoContainer (Host.js:39)
at Object.renderSubtreeIntoContainer [as unstable_renderSubtreeIntoContainer] (Host.js:39)
at HTMLDocument.r.renderFrameContents (Host.js:41)
at HTMLDocument. (/@user-davidsporer:24)
Host.js:47 Uncaught TypeError: Cannot set property '/sites/support/node-591948280494e@user-davidsporer' of undefined
at t.value (Host.js:47)
at HTMLDivElement. (Host.js:41)
at Object._renderSubtreeIntoContainer (Host.js:39)
at Object.renderSubtreeIntoContainer [as unstable_renderSubtreeIntoContainer] (Host.js:39)
at HTMLDocument.r.renderFrameContents (Host.js:41)
at HTMLDocument. (/pass-templates@user-davidsporer:24)

[cvette]

This seems to be a problem with the SelextBoxEditor and custom data sources in the new UI. Your best bet is to override the language property and define the options in the node type definition yourself.

You can find the supported language values in: Libraries/geshi/geshi/src/geshi/