I had a similar problem. I ended up taking the following steps which ended with successful completion of the lesson.
In my problem, the output screen showed an error. I think it was unexpected T_ECHO. No matter how i changed the programming code it wouldn't come off this error. So I edited the code to the correct configuration of additional punctuation, copied the entire PHP section of code by highlighting it and right clicking on the highlighted area. I then hit Backspace to delete the PHP section, hit the reload button on my browser, then hit reset code at the bottom, then pasted in the correct code over the top of the exercise's reloaded code.
This was able to bypass the intermediate steps of parsing every keystroke. Not sure what the problem was, but there is definitely a bug in this exercise., This happened specifically in the "All on your own" section.