Directory index forbidden by Options directive error in Cakephp

Directory index forbidden by Options directive error in Cakephp

Getting Directory index forbidden by Options directive error when trying
to upload images but not getting that every time, so not know the exact
senario, i have check the error_logs of apache. The .htaccess in webroot
is
`<IfModule mod_rewrite.c>
RewriteEngine on
RewriteRule ^$ webroot/ [L]
RewriteRule (.*) webroot/$1 [L]
</IfModule>`
I fixed this using +Indexes in < Directory > but i don't know why i'm
getting the error so some images only they are of ~700 KB and ~1500 X 1700
in size.