I haven't had the issue either but here is a site
https://support.apple.com/en-us/HT203829 This file is installed with OS X and should not be deleted. In some cases, it may be visible in the Finder. The file can be hidden again using the following steps.
1 Login as an Admin user.
2 Open Terminal (located in /Applications/Utilities).
3 Enter the following command, then press the return key:
4 sudo chflags hidden /mach_kernel
5 Enter an Admin password at the "Password:" prompt.
6 Quit Terminal.
This may prove useful for some with the issue
