Here's the issue as I see it with this update (KB4058258) there is something that goes wrong when you download this Cumulative Update via the "Automatic Download" function in Windows.
Everybody here (and I mean EVERYBODY) has found it much more satisfying to download this update from the Microsoft Update Catalog https://www.catalog.update.microsoft.com/Search.aspx?q=KB4058258
as a "Stand Alone Installer" (you save it to your Desktop like this:
First you select the download you need for your device. Windows 10 or Windows Sever 2016 or whatever. This example happens to be the 32 bit installer:
Now, you select the blue text there to get your options...save and so on:
then you click the arrow next to save so that "save as" will show in your menu and then clicking that to download the installer like this:
Once you have saved it to your Desktop (for easy location later) you wait for it to download, then run it, then reboot/restart to clear out the messages in Windows Update that will still be telling you to update it and you're all set.
We hope. 🤞
It works for most people, anyway.