WHMCS version 7.5.0 was released on 2 April 2018.
The updated theme versions introduce full compatibility for WHMCS 7.5.0, including SiteLock integration via WHMCS Marketconnect, new marketing emails consent feature, new domain renewal process, domain pricing page and new product upgrade procedure.
Further details of each release can be found in the accompanying release notes and change-logs.
The updated theme versions are compatible with WHMCS 7.5.0 only. They are not compatible with earlier versions of WHMCS.
You can find further details on the changes in WHMCS version 7.5.0 in the WHMCS release notes.