I removed the #from the htaccess for custom image not found but it's not working it's showing not found on all images...
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule images/.+\.(gif|jpe?g|png|bmp) - [NC,L,R=404]
RewriteRule images/.+\.(gif|jpe?g|png|bmp) content/images/system/default/404.gif [NC,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule images/.+\.(gif|jpe?g|png|bmp) - [NC,L,R=404]
RewriteRule images/.+\.(gif|jpe?g|png|bmp) content/images/system/default/404.gif [NC,L]