USB fails to create, ->10.11.4+ Skylake Starter Guide

[sjpapa2]

kext-dev-mode=1 is a kernel flag that allows you to use patched/unsigned kexts.
Some kext installer tools see it fit to patch msdosfs.kext without your permission.
On a real Mac, you set kernel flags in nvram (boot-args).
Suggest you restore msdosfs.kext to vanilla if you didn't intend on patching it.

How can I restore msdosfs.kext?
Never intended patching...
Where can I get the original? and how install in MacBook?

 

[RehabMan]

How can I restore msdosfs.kext?
Never intended patching...
Where can I get the original? and how install in MacBook?

You can restore from install media that matches the version you have installed. Or by running the SS X installer itself (don't erase the target partition and it is a "refresh" instead of "fresh install").

 

[sjpapa2]

You can restore from install media that matches the version you have installed. Or by running the SS X installer itself (don't erase the target partition and it is a "refresh" instead of "fresh install").

I hve never done this. I have the Yosemite package. Clicking install starts the familiar installation. Can this be done from the OS disk? Never came across to a 'refresh'. What is 'SS X installer'?

Many thanks for the very useful hints!

 

[sjpapa2]

repaired msdosfs.kext

 

[sjpapa2]

After repairing msdosfs.kext: finally progress