Media Creation Tool Error 0x80042405 0xA001B

I've had the same issue as op; needed to create a USB recovery drive to resolve an issue with Windows 10 on my Surface Go.  During the process (I think during copy, near the end), it failed with same error "0x80042405 0xA001B".  I have since tried multiple combinations of:

1. 3 different USB drives, all >16GB, all unused
2. Different USB ports
3. Formatted USB w/ Explorer (FAT, FAT32, NTFS)
4. Copied exe to usb and ran
5. Ran as administrator
6. Tried on 2 different PCs (none of them the problem PC)

No solution.  8 hours wasted, original problem PC still unusable.  Would be great if released software worked.  😐

Reading through this thread and other references, I finally found the following steps that solved my issue, maybe it could help you.  I am sure some of this is duplicate work (setting a partition then formatting), but I don't care about efficiency, I care about solving the problem.

1. Download the Media Creation Tool (MCT) to your hard drive.
2. Insert a >16GB USB in any USB slot
3. Use the diskpart tool to format the USB
   1. Run the tool; Windows key, then type diskpart
   2. See all your disks to know which is the USB you are after; list disk
   3. Match the size listed to your USB and select it; select disk x (x is the listed Disk #)
   4. Remove all partitions and volumes; clean
   5. Create a partition; create part primary
   6. Select the new partition; select part 1
   7. Make it the partition; active
   8. Quick format the USB as FAT32; format fs=fat32 quick
   9. Close diskpart; exit
4. Run the MCT and create the USB boot drive
   1. Run the MCT as an administrator from your computer; right click the exe, select run as administrator and accept any prompts
   2. Select the correct options you want in the tool; e.g. for another computer, select windows options, select USB drive you just formatted
   3. Wait…. Wait…. Wait….
   4. Success.
5. Use your newly created USB Windows 10 recovery drive as you see fit.

Good luck

Took me a few tries (and formats), but I finally managed:

Quick format USB drive NTFS.

Put 'MediaCreationTool1903' onto USB drive.

Right-click and 'Run as Administrator'.

Installation media for another PC...

Architecture BOTH (x32 and x64)

When the File Explorer window on my USB closed, I pulled it back up and left it selected for the entire duration thereafter.

Nothing else I tried, several times, worked. It finally did and the aforementioned is how (I did NOT delete the temporary files, '$Windows.~BT' and '$Windows.~WS' generated in C:\ and nor did I screw around with Diskpart as I see suggested ad nauseam for this problem).

Using a 8GB PNY flash drive (and used my chassis front USB 3.0 port), which I'd already used for this back in 2016.

Hopefully this helps somebody. My error was also 0x80042405

• 0xA001B.

Thanks to Greg Carmack and JavierLarroulet this worked, just wanted to share the variation of my process to successfully create the bootable thumb:

First: Manually make the thumb drive bootable with Diskpart:

• Open an elevated command prompt and run diskpart.
• Once inside Diskpart, type list disk and you'll get a list of all storage drives in your computer. Take a note of the number that matches your thumb drive (it'll read, for instance, Disk 2 (I'll use 2 for the sake of this example)
• type select disk 2 <enter>
• type clean <enter>
• type convert mbr <enter>

====== I couldnt perform the partition, nor format with diskpart, so I just went to File Explorer and formatted with FAT32 and

quick format enabled =================

Second: Run the Windows Media Creation Tool IN ELEVATED MODE

Basically, right click on the executable file and "Run as administrator". You'll get the usual UAC prompt. Accept and let the media creation tool do its thing, with the USB bootable option of course. 

Details:

• Following the successful steps mentioned above, I just needed 1 try to create the thumb drive bootable.
• Before trying these steps, I formatted the USB(FAT32) without the clean up(diskpart) nor the "Run as administration" option of the creation tool, and it failed twice at the end of the installation media process (totally frustrated, every try took about an hour or more).
• Issue: My Asus restarted because of update **KB4023057,**after that windows wouldn't boot, I tried every solution mentioned here https://support.microsoft.com/en-ca/help/12415/windows-10-recovery-options that involved NOT to create a bootable drive with installation media, but eventually, I had to reach the option to restore to an specific restore point (I tried that without the drive and it didnt worked). Fortunately, I didnt have to reach to reinstall win 10, I didnt want to lose my information. So this issue brought me to create the bootable drive and hours of headaches. BTW restore my windows 10 with thumb bootable  drive worked.
• Im a newbie.
• I used an 8 GB USB Stick for x64 version.

Hope this helps you guys, last 3 days have been horrible but finally made it.

Read the instructions.

http://www.yourwindowsguide.com/2017/04/update-to-windows-10-creators-update.html