MWException occurs when saving a form with source code

Describe the issue / Steps to reproduce:
I tried to create a new form by adding a new Formular page.
Within this form, I am using source code (markup) to render the form.
When I attempt to save the page, an error occurs and the form is not saved.

Expected behavior:
The form should be saved successfully and rendered correctly on the page without any error message.

What was the error message/error log?
[b48eb9adbc2587b20cb8193b] Caught exception of type MWException

System info:

OS: Windows 10

Server: Apache 2.4

PHP: PHP 7.4

BlueSpice version: BlueSpice 4

Browser version: Google Chrome (latest version)

Hello MMer,

to further investigate this, we would need more info. Could you please troubleshoot according to our information here:

https://en.wiki.bluespice.com/wiki/How_to_debug

Greetings

Margit