I have tried installing this update from the Action Center, as well as from the Microsoft website to no avail. How can I get it to install? I have Windows 8.1 64-bit. Thank you!
Another possible cause is your anti-virus if it is a third party one and not the included Defender on 8.1Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.
If you are using Windows Update, the latest SSU (KB4540725) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.
Please share the solution as it may be helpful to others who may experience the same issue.I was able to fix the issue myself through troubleshooting.
Mark it solved please, click mark solved on your opening postIf that does not work - I suggest you try here
https://support.microsoft.com/en-gb/help/4027322/windows-update-troubleshooter