WordPress media upload multiple images

Make sure the permissions for the upload folder are set correctly, and that none of WordPress’s files have been deleted. Also, try disabling all plugins. If it still doesn’t work, try adding this to the .htaccess file:

<IfModule mod_security.c>
SecFilterEngine Off 
SecFilterScanPOST Off
</IfModule>

Test and see if it will work on a small image, but not a larger one. If this what happens, add this to your .htaccess to increase the memory:

php_value memory_limit "128M" 

Also check to be sure there aren’t any strange rules in your .htaccess file. In the WordPress permalink settings, it updates the file if it has permission, or tells you what you need to change.