An update was released today that adds SHA-2 code signing support to Windows 7 SP1 and Windows Server 2008 R2 SP1. If this update is not installed, these Windows operating systems will no longer be able to receive Windows updates starting on July 16th, 2019. As there are flaws in the SHA-1 algorithm that make it less secure, Microsoft has stated that Windows updates will only be signed using the more secure algorithm going forward. Microsoft also released KB4484071 for those using WSUS 3.0 SP2.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-7-gets-sha-2-support-to-enable-future-updates/