Updated Requirement - Access (runtime) 2016

Important Notice: As of CMS version 19.4.3 Access 2016 is required. CMS will no longer work with Access 2013.
Before upgrading to the latest version of CMS (version 19.4.x or later) be sure to check which version of Access you are using.
If you install the new version (whether you download it from the support website, or via CMS Connected) and this requirements is not met, CMS will not function properly or at all!
How to check your Access Version:
  1. Open the Windows Control Panel
    (Click the Windows Start and type Control Panel).
  2. Open the Programs and Features app in the Control Panel to see a list of programs you have installed on your computer.
  3. Scroll down the Microsoft and see what versions of Office or Access you have.
    If you have "Office 2016 Professional", or "Access 2016" or "Access Runtime 2016," you're fine.
    If you have "Office 2013 Professional" or "Access 2013" or "Access Runtime 2013," you need to upgrade.
How to upgrade Access
Regardless of what you currently have installed, we recommend that you remove the older versions of office and Access Runtime and then install the full version of Office Professional 2016 (32 bit) which includes access. This will ensure full compatibility between Office applications (Word, Outlook, Access).

You would need to obtain a license for Office 2016.
One easy option is to use Office 365 Personal (1 computer) or Home (up to 6 computers),
If you don't want to upgrade office, how you proceed depends on what you currently have installed