### Steps to reproduce

1. Create WP

2. Open Workpackage and click into the description-field

3. Click Icon to "Switch to Markdown source"

4. Click Icon to "Switch to WSIWYG editor"

5. Error-Text will show up
"An error occurred within CKEditor
unexpected-error Read more: https://ckeditor.com/docs/ckeditor5/latest/support/error-codes.html#error-unexpected-error Original error: TypeError: Cannot set properties of undefined (setting Begin of the insertion'isEnabled')"End of the insertion Begin of the deletion 'isEnabled')"End of the deletion


### What is the buggy behavior?

* Switching back form Markdown to the WYSIWYG editor is not possible


### What is the expected behavior?

1. Switching back to the WYSIWYG editor should work.


### Begin of the insertion

End of the insertion Begin of the deletion Important note

_Please note that unless you are a contributor to OpenProject, you can no longer edit this bug report after saving. You can still add new comments, new images and upload attachments though, but updating description or modifying fields will not be possible after saving. Please make sure that all necessary information and attachments are added, and the following attributes are set:_

End of the deletion ### **Logs**

_"_
index.js:903
Uncaught CKEditorError: unexpected-error
Read more: https://ckeditor.com/docs/ckeditor5/latest/support/error-codes.html#error-unexpected-error
Original error: TypeError: Cannot set properties of undefined (setting Begin of the insertion'isEnabled')End of the insertion Begin of the deletion 'isEnabled')End of the deletion
   at button-disabler.js:42:13
   at Array.forEach (<anonymous>)
   at pk (button-disabler.js:34:26)
   at op-source-code.plugin.js:86:5
   at Lu.<anonymous> (op-source-code.plugin.js:94:4)
   at Lu.fire (index.js:1280:28)
   at nu.<anonymous> (index.js:2902:30)
   at tt.o3 (index.js:989:26)
   at tt.fire (index.js:1280:28)
   at HTMLButtonElement.t3 (index.js:2681:18)

_"_

### Screenshots and other files

Begin of the insertion[https://community.openproject.org/api/v3/attachments/922215/content](https://community.openproject.org/api/v3/attachments/922215/content)End of the insertion Begin of the deletion [https://community.openproject.org/api/v3/attachments/922215/content](https://community.openproject.org/api/v3/attachments/922215/content) End of the deletion

### Environment information

Begin of the insertion<br>End of the insertion Begin of the deletion _Please check and fill out the following details to help us identify in what versions and distributions of OpenProject the error occurs_End of the deletion

Begin of the deletion **OpenProject installation type**

* Packaged installation

* What distribution?


End of the deletion **OpenProject version**

_17.5.1_

_17.7.0 (Edge - https://stadt-koeln.openproject-edge.com/)_

**Browser**

* [x] Chrome
* [ ] Firefox
* [ ] Safari
* [ ] Mobile Safari
* [ ] Other (please specify)

**Operating System**

* [x] Windows
* [ ] Mac OS X
* [ ] Mobile iOS
* [ ] Mobile Android
* [ ] Linux (please specify distro)
* [ ] Chrome OS
* [ ] Other (please specify)

**Language**

_german / englisch_