Hi experts,

I am trying to filter a tree using CopyTree(), but this does not seem to work. I have searched through the forum but nothing gives me a working solution.

Here’s a little snippet to reproduce my problem which I wrote using pyROOT:

```
import ROOT
file = ROOT.TFile('/afs/cern.ch/user/s/sandrean/public/root/mc16a.PowhegPy8_ZH125J.root')
tree = file.Get("CollectionTree")
tree_filtered = tree.CopyTree("HGamEventInfoAuxDyn.isPassed == 1")
```

This gives me segmentation error.

Hoping the experts here can help!

Best regards,

Yosse

_ROOT Version: 6.16