If max_post_upload and max_file_upload in PHP has been set,
and there is a setting in Apache2.conf or ModSec config files of LimitRequestBody set high enough
then possibly a .htaccess file will work.
- Go to the directory with the upload php file in it ( the file or page throwing the error.)
2 . Make or edit .htaccess
3 . Edit or create a line with
LimitRequestBody 20971520 in it.
Save the .htaccess. Set permissions. ( 644 and apache owner)
Possibly restart apache.
Tada . Hopefully fixed.
This setting sets that limit for this folder only - which is one way to avoid a global setting in php and apache which makes you open to large packet / load DOS attacks.
LimitRequestBody 0 gives you unlimited uploads.