After configuring a Cisco Meraki device's static IP address either from the dashboard or via the my.meraki.com Uplink configuration page, the device may report "Bad IP assignment configuraion" in Dashboard:
In the case that the device cannot get an ARP reply from its default gateway, it will revert back to using DHCP for its IP configuration. This is an intended function to bring the device online; if the device can't reach its default gateway, it will never report to Dashboard.
The static IP will still be configured on the device if you go to the Uplink configuration page on the Local Status Page or, for MS switches and MR access points, on the device's details page in Dashboard under "set IP address". Even though the device will have a different IP via DHCP, it will continue to ARP for the gateway configured statically. As soon as the device receives an ARP reply from that gateway, the AP will switch to its static configuration:
In the above packet capture, the Meraki AP has already obtained an IP via DHCP because it has received no ARP reply from its gateway 192.168.15.1. However, the AP will continuously send out ARP requests for its statically configured gateway. Until it receives an ARP reply from the statically configured gateway, the dashboard will continue to report "Bad IP assignment configuration".