Error in <DavixOpen>: can not open file with davix

Hello all:
While following through the ROOT 6 analysis workshop I came across a problem when trying to access a root file on the internet, (Not on my machine).

When ever I type
TFile* file = TFile::Open(“”);
into root as prompted by the tutorial. I get a message that says it cannot be accessed because the issuer is not trusted.

The error I get is below

Error in : can not open file with davix: Neon error: Server certificate verification failed: issuer is not trusted (6)

I am running ROOT 6.03/04 Built for macosx64 (Im running Yosemite)
From tag v6-03-04

Any ideas on what i can do to access files on the internet??


This typically indicates that you do not have enough information to validate the certificate of the remote peer, i.e. in this case. Which means that you do not have installed the CA issuer of the certificate, which is COMODO.

You can perhaps play with the settings in … x-tutorial
in particular Davix.GSI.CACheck .

G Ganis

Great thanks for the help!
I will try this


Indeed adding

Davix.GSI.CACheck: n

to your system.rootrc or .rootrc should avoid the problem in this case. It may be that Davix hasn’t been able to find the CA in the system keychain, although it is there. (COMODO is a standard trusted root certificate in OS X Yosemite). I will check if this is happening.


Visiting the link you sent me actually fixed my problem, in a a sort of unorthodox way…

I installed mac ports and followed the prompts in the page.
sudo yum install root root-net-davix

but instead used
sudo port install root6 root-net-davix since I am using macports and ports said root was obsolete.

I did not realize until a few minutes in that this meant it was going to install both “ROOT6” and

I removed the binary files for ROOT6 that I had installed previously and let Macports run.
“root-net-davix” failed to install though. (later realized it wasnt needed.)

ROOT 6.04/00 is now installed and runs davix great.

I guess I would recommend that all mac users install ROOT by this method,
downloading MacPorts and running sudo port install root6.

Thanks David