Sometimes when you edit the .htaccess file in cPanel, the lines must wrap and this causes a line break.
The line break is a common reason for site errors.
To fix this, open a text editor (like NoteTab Light) and paste your .htaccess code in.
- Be sure that Word Wrap is off.
- Save the file as htaccess.txt
- Upload this new file to the proper directory.
- Rename the current .htaccess to htaccess-old.txt
- Rename htaccess.txt to .htaccess
To avoid further problems, don't open this .htaccess in cPanel anymore.