Version 2.7.5 of Retail Man POS was released Sep 2019.
This is a major release of Retail Man POS, so new licence keys are required to use Version 2.7.
Please see the link below for more information. The cost of upgrading to Version 2.7 starts at USD80 / GBP59.17 for a 1-user system
https://ezisolution.wordpress.com/2019/09/23/version-2-7-5-of-retail-man-pos/