On Mon, 17 Apr 2017, Pat Riehecky wrote:

> Scientific Linux 6.9 i386/x86_64       Apr 17, 2017
>
> SL 6x users:
>   Please run   yum clean expire-cache

That did not work for me, but
 	yum clean metadata
did.

Sorry, I have lost the original error message, but it was to the effect 
that the cached metadata was newer than the downloaded metadata
and I was using a server or mirror at ftp.scientificlinux.org.



> SL Mirrors should consider running a sync at this time.