Looking for UCRT I found this link where Microsoft explains the introduction of the Universal CRT: link
Especially interesting the section "Distributing Software that uses the Universal CRT". Quoting the page:
The Universal CRT is a Windows operating system component. It is a part of Windows 10. For Windows versions prior to Windows 10, the Universal CRT is distributed via Windows Update.
Basically, the ucrtbase.dll file is part of the operating system, not the compiler. As they suggest, installing the latest operating system updates should fix it. It is also available here: link
As they say:
Microsoft Visual Studio 2015 creates a dependency on the Universal CRT when applications are built by using the Windows 10 Software Development Kit
This dependency is added when configuring Windows 10 as an operating system target. If you would like to eliminate dependency, you should be able to do this by adjusting the target of the project to an earlier version of Windows.