Symptoms

Update set commit encounters the following error when trying to bring an ACL:

Skipping ACL Update: sys_security_acl_<sys_id> for table<table_name> as this instance runs in default allow mode and there are no other table level ACL's for table: <table_name>."

Cause

System property glide.sm.default_mode set to allow.

Resolution

One can create the ACL via UI /GUI manually.

Additional Information

The system property glide.sm.default_mode is set to deny by default in all new instances. No one can change this setting. Some old few instances have this set to allow. This will only occur for those few instances where the property is set to allow.

Here's documentation regarding this property:

https://docs.servicenow.com/bundle/london-platform-administration/page/administer/security/concept/c_DefaultDenyProperty.html

It states that when the property glide.sm.default_mode is set to value "allow":

Allow Access: The wildcard table ACL rules allow the read, write, create, and delete operations on all tables unless there are specific table ACL rules in place to restrict such operations.