I experienced the same problem using CSS Form Builder 2.0.1 - but after adding a progress bar to the form.
The exact error message is
Parse error: syntax error, unexpected '[' in C:\xampp\htdocs\sidi-cedis-v3\bewerbung.php on line 26
and when I put '$_POST' in front of the '[' it works fine.
Also I think I use the latest version of Form Builder.
Maybe this helps or maybe the problem is already solved in another thread?
Best regards, Thomas