Error saving TH1F histogram in TDirectory

Newbie
, ,
1

ROOT Version:JupyROOT 6.30/02_

Hello experts,
I am trying to save a TH1F histogram in a TDirectory of a .root file. When I then try to open this .root file with TBrowser for example, I get these error lines:
Error in TList::Clear: A list is accessing an object (0x288d9f0) already deleted (list name = TList)
Error in TList::Clear: A list is accessing an object (0x288de70) already deleted (list name = TList)
… (many more lines)

This is the code to produce this:

outfile = ROOT.TFile("data.root", "RECREATE")
nomi = outfile.mkdir("nominal")
nomi.cd()
reco_ttbar = ROOT.TH1F("reco_ttbar_m", "data_ttbar_m", 87, 0, 2001)
for v in pred:
    reco_ttbar.Fill(v)
reco_ttbar.Write()
outfile.cd()
outfile.Close()

When I dont do .Close() these errors disapear, but then of course I get the warning about not properly closing the file. Hope someone can help me out.
Cheers

2

Hello,

This seem to be the technical issue cause by the difference in ROOT version.
If you create the root file by any version >= 6.30, then you read the same file using any version < 6.30, this error will show up.

You may want to try reading it by ROOT 6.3X or above.

Cheers,
Hoa.

3

Hello Hoa,

indeed this was the problem. Thanks!
Cheers

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