Unetbootbin should work fine for Windows ISO less than 4G with FAT32 partition. However, Windows 10 ISO with latest update is larger than 4G so you have to format the USB to exFAT32 before burning.
Here are the tools that work fine on Mojave 10.14 5 on my MacBook Pro:
You can also set ...
I would say you need to take your machine in for repair. You have detached all external devices that you can: with possible exception of mouse&keyboard?
Sometimes if volumes don't appear in Startup Manager (what you get when you hold down the Option key at startup), you need to reset the Mac's PRAM, NVRAM. Shut down the Mac, then power it ...
It should also be noted that you can type brew info <formula> which will tell you whether or not a formula is installed. You can parse the response for "Not installed" and then run the installer if it finds the string.
If you go ahead and run the 19MB installer (/Applications/Install macOS High Sierra), it will download the remaining install files and place them under /macOS Install Data.
Simply abort the install when it asks which disk you want to install to.
To restore the ability to create install media, do the following:
Open Terminal and run: sudo -s
Enter admin ...
Reboot while holding Command-R to bring up the recovery mode
Open disk utility from the window that appears, click on the main hard disk and press the "mount" button. If it asks for a password the users login password will work.
Exit disk utility
Open Terminal from the "Utilities" menu bar item
Type: cd /Volumes
A list of hard disk volumes will be ...
Yes - internet recovery fails to see an internal drive (or external drive), it's almost always time to swap hardware / repair things.
You could on some rare instance need one last SMC / NVRAM reset and try again on a different network internet recovery if you think the checksum / validation that the boot image is correct was somehow failing at the same time ...
I am also facing this issue of the installer being 16 MB. I tried several times but out of luck. Then I downloaded the DMG files directly fro Apple's site and used it to update my system
This is most likely related to two factor authentication. I was getting this error message when trying to download MacOS High-Sierra from an El-Capitan installation. What fixed the problem for me was to first download something else from the app store. I as then asked to authenticate with tfa and subsequently was allowed to download macos.