For a workaround, I heard some people claim you have to disconnect your Smartphone if it is connected to your PC via the Your Phone app. Disconnect all external/removable drives as well, delete everything in the "Windows\SoftwareDistribution" folder, and try again.
I currently have Slow build 18356.16 on my PC. The auto update build 18362.1 failed to install. I created an ISO of build 18362.1 and when I started to install it reported it could not save existing settings and reported I was trying to install an older version of Windows???? I did not want to do a fresh install at this time. Also, any way to verify I did indeed create an ISO of the latest build? I used the command: D:\WINDOWS_10_BETA\18362.1_amd64_en-us_8865774c_convert\aria2_download_windows.cmd
Right click on ISO Click on Properties / Details and see if it shows ISO Build # or you can mount ISO & check version # of setup.exe Then unmount.
In the Feedback Hub, people are reporting upgrade issues which is a negative otherwise I can't agree with you here, from using this build, it feels real solid. edit: people who upgraded in the Fast Ring had no issues (before it came to Slow yesterday).. just thought i'd mention that.
Start Menu is crazy slow on my systems. It's such a huge delay from hitting the Windows Key on the keyboard until the start menu is showing.
Stop please, even MS don't know April update build exactly. You know there is always something unpredictable.
My negative comment regarding build 18362.1 was specific to the current install issues over earlier builds in the SLOW ring. I thought that could prevent it from becoming an RTM build if the issue was not corrected. Beyond that I have to withhold comment as to the overall performance of the build since I could not install it. Apologies for premature negativity. I tried a different build version "Windows 10 Insider Preview 10.0.18362.1 (19H1_RELEASE) amd64" to create an ISO file. It did start the install process and allow me to keep all apps and settings to start with but the installation failed after reaching 100% and reverted to the previous 18356.16 build.
The iso I created would not install over build 18356.16 but it did successfully install on an older laptop that had the version 1809 Fall release and preserved apps and settings, so I know the iso I created was “good”. Whoever comes up with a way to trick this build to install over 18356.16 will have hundreds of appreciative beta testers.
Im just waiting for Microsoft to fix it themselves, pretty sure we'll see a new one around Tuesday time, they will want to fix it pretty quickly just in case it affects users not on the insider program, I can wait a couple of days.