The problem is solved.
System -> System file management
i searched the "Lokal_subnet_1" by ctrl+f
decryption-policy
rule name 1decryption_policy
disable
source-zone trust
destination-zone untrust
source-address address-set Lokal_subnet_1
service https
action deny
rule name decryption_policy
disable
source-zone trust
destination-zone untrust
source-address address-set Lokal_subnet_1
service https
action decrypt profile ssl_detection_profile
And then , i go encrypted traffic detection.
But this rule is disable !!!!!!
i deleted this rule. And then i can deleted lokal_subnet_1
if a rule is disabled ,is still effective ?