Plugin “Remove Slug From Custom Post Type” gives 404 Error

This plugin did all I wanted, but it started giving me 404 errors, which go away after a while but I'm worried they'll come back. I do get this error while posting a new listing (real estate theme)

RewriteRule ^agencies/(.+)$ /$1 [R=301,L]
RewriteRule ^agent/(.+)$ /$1 [R=301,L]
RewriteRule ^faq/(.+)$ /$1 [R=301,L]
RewriteRule ^/(.+)$ /$1 [R=301,L]
RewriteRule ^package/(.+)$ /$1 [R=301,L]
RewriteRule ^/(.+)$ /$1 [R=301,L]
RewriteRule ^pricing/(.+)$ /$1 [R=301,L]
RewriteRule ^property/(.+)$ /$1 [R=301,L]
RewriteRule ^transaction/(.+)$ /$1 [R=301,L]
RewriteRule ^/(.+)$ /$1 [R=301,L]

I changed the .htaccess file with these but the error doesn't go away, I even changed the permissions to 777. Please hel

via Chebli Mohamed