pkgng upgrade "unable to find catalogs" - with key installed

[Juanitou]

I have the same error, but in my case it happened after updating a few 
minutes ago my 10.0-RC4 system to -RC5. Yesterday, I upgraded a lot of 
packages with "pkg upgrade" without issues. Now, just after  upgrading 
the system through "freebsd-update upgrade", the same command triggers 
the "unable to find catalogs error".

pkg itself is up to date.

Any ideas?