Scope, 192.168.1.0, is 95 percent full with only 1 IP addresses remaining.
Use the DHCP application from the "Administrative Tools" to review the current DHCP leases, and terminate any if possible.
Navigate to DHCP - servername - Scope - Address Leases.
You can right-click a lease to delete it. To avoid long-term problems it is recommended that you extend the IP range of the scope in question.