Help with the Extended Architect

Hi,
I have a problem with the text I would like to add in the extended Architect: I get the following message:

“Apparently you are currently adding HTML markup or other special characters. Once all HTML tags are closed, the preview will be available again. If this message is still displayed, check your input for special characters and try to remove them”

Can you help me with this?

What are you typing in? Sounds like something you have is special characters which does not work and causes it to break

I just want to modify the text I have already written in the text field. I tried already to create a new text but when I openend the text field its already filled with the code.
I can send a Screnshot