Hello/Hi/Greetings,
After I "successfully" login to admin on piwigo 2.9.0 I get this "full screen message" nothing else.
I can't get to the administration page.

Piwigo encountered an unrecoverable error
[Hacking attempt] the input parameter "redirect_decoded" is not valid
#1    check_input_parameter /home/webbbsite/public_html/pictures/identification.php(50)

and the error comes up on this webpage
http://www.webbbsite.com/pictures/identification.php


Piwigo version: 2.9.0
PHP version: 7.0
MySQL version: 4.7.3
Piwigo URL: http://shootedit.com/pictures
Server type: MariaDB

I've tried setting PHP to version 5.6 and 7.1 both don't work.