I solved it by myself.
It was a server side firewall (mod_security). After contacting my hosting service, they added the string "1=1" in the white list. Now it's okay.
I hope this can be useful for somebody.
I solved it by myself.
It was a server side firewall (mod_security). After contacting my hosting service, they added the string "1=1" in the white list. Now it's okay.
I hope this can be useful for somebody.