Test Page breaks with this !include command

[mstitde-a11y]

Describe the bug
When entering a !include -c command that references the test page itself, the page is not usable nor editable anymore.

To Reproduce
Steps to reproduce the behavior:

1. Create a new Testpage
2. enter the !include -c command
3. Try to reopen or edit the page
4. See that the page will be stuck loading endlessly

Expected behavior
The page should be visible, editable with a hint what is wrong or an error message.

Configuration:

• OS: Windows11
• Browser chrome
• Version 20230503 of FitNesse
• Test System ?
• Plugins ?