Steps to reproduce:
1. Create a new article "test".
2. Edit one of its RichText fields e.g. "Intro".
3. Type for example: "test1 [Shift+Enter] test2".
4. Highlight "test1" chunk of text and open link toolbar.
5. Type some random link and confirm.
The JS error occurs:
after that, there is no toolbar present while editing content in RTE.
Link is added without JS error and editing content is still possible.