@deigo Welcome to the Rockstor community.
Is this a Rockstor v3 variant. That now has a rather old CentOS base and we no longer release updates for it. Plus there is a known ssl issue that may well be causing your:
In short this is down to out-of-date SSL certs in our CentOS base used in v3 Rockstor.
@Flox has a nice explanation and work around here:
However you would be far better off re-installing our v4 “Built on openSUSE” as that is what we are now working on. It’s also very nearly at stable status (Release Candidate 10), and pre-build installer can be downloaded from our website:
Take a look at our v4 installer how-to here: Rockstor’s “Built on openSUSE” installer — Rockstor documentation
Hope that helps.