There is a potential issue for customers who have Cambium Rseries devices running device firmware older than release 4.3 and upgrading to 4.5-R7. All such customers wanting to upgrade to 4.5R7, must follow a 2-step upgrade procedure as described below. Directly upgrading from such old firmware to 4.5-R7 might lead to device inaccessibility.
Customers running 4.3 or newer firmware will not be affected by this issue
All such devices running firmware older than version 4.3 MUST NOT be directly upgraded to 4.5-R7 or higher version, instead they should first be upgraded to 4.4.2-R2 firmware (available on the Cambium support site). Thereafter the devices should be upgraded from 4.4.2-R2 to 4.5-R7 firmware.
Please follow below link to upgrade to 4.4.2 from 4.2
http://community.cambiumnetworks.com/t5/cnPilot-R-Series-Home-Small/Upgrading-cnPilot-R-Series-Home-Routers-from-4-2-Release/td-p/98998