Your data is indeed over multiple blocks.
These blocks separately are not correct JSON, hence the error message. Not sure how you managed to seed this parameter component with the data like this.
If you intend to get the same text of the panel in the text parameter you should make it into one long string, something along the lines of
your_json_as_one_line = "".join(your_json_over_multiple_lines.strip().split())
That you can copy&paste into the text parameter through its parameter menu.
With everything as one line so you have proper JSON you’ll get