Even though wild cards (*) are allowed by the documentation, they are allowed only to be set at the last octet of the IP address (eg. 192.168.10.*). Spaces are also not allowed, as explained at SAP Note 2275275.
If an invalid entry such as 192.168.* is set in the same line along with other client hosts, the entire line gets invalidated.
See SAP Note 2423054 – Message Server ACL file