Interactive Book: Please wait while the content is loading… message after an edit

In ILIAS (v7.27) when I create an Interactive Book element and edit this I will no longer be able to see the content, but instead the message: "Please wait while the content is loading… ". Which will never change.

This can be somewhat fixed by making a copy, which I can edit once again. But then I have to keep making copies with every edit which is not ideal.

This happens on desktop, Microsoft Edge as browser and the H5P version is 4.1.21 if I am correct. There have been no known recent updates of the environment.

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Interactive Book: Please while the content is loading… message after an edit
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