Hi and long time no see, @usmannasir! 
You might want to check this as well in CSF. A similar text check (with the latest release and the new UI) is blocking edits to the config files in CSF with the blocklists. See my post here:
Hi and long time no see, @usmannasir! You might want to check this as well in CSF. A similar text check (with the latest release and the new UI) is blocking edits to the config files in CSF with the blocklists. See my post here: