Hi @artlbv ,
and welcome to the ROOT forum!
I think the interesting part of the error message is TTree leaf l1tJetBXVector_caloStage2Digis_Jet_RECO.obj.data_.puDonutEt_[4] has both a leaf count and a static length. This is not supported. (the missing dictionaries will be a problem if you want to read those classes, otherwise they are harmless, and the PyROOT “template method resolution failed” is likely a consequence of the first error I mentioned.
Now – my educated guess as to why RDF can’t read l1tJetBXVector_caloStage2Digis_Jet_RECO.obj.data_.puDonutEt_[4] is that TTreeReader (which RDF uses internally for I/O) does not support that case. But I would have to verify this claim because RDataFrame pre-emptively errors out before even trying to read such a branch with TTreeReader. Would you be able to share a file (even with just that one branch, even with just a few events) that reproduces the problem, so I can take a look directly? If not, could you please try to read that branch with TTreeReader? See examples at ROOT: TTreeReader Class Reference .
Cheers,
Enrico