Comment 3 for bug 1886241

Hi Olivier,
Thank you very much for your reply. First of all, I just want to let you know that I'm just a beginner with MG5aMC and I'd like to apologise in advance for my ignorance and, also, in case I'm just doing something silly.
As I said in the OP, MG5aMC was working perfectly fine until it got updated. I reinstalled lhapdf6 via the MG5aMC command 'install' when I first got the issue to see if that fixed it but made no difference. I then tried a new fresh MG5_aMC installation followed by installing the usual packages (i.e. MadAnalysis5, ExRootAnalysis, Delphes, lhapdf6, etc.) but this didn't sort out the problem either.
I haven't set any environmental variables for LHAPDF, just for ROOT as suggested in one of the MG5aMC installation guides I found in the internet. (FYI, I didn't set any environmental variables for LHAPDF either the first time I installed MG5AMC when it was working fine, before it was updated and got broken.) May you please indicate what environmental variables for LHAPDF I would need to set up to see if that helps?
Not sure if this is important or not but when I set in the run_card 'pdlabel = LHAPDF', then it downloads the lhaid number that I indicate, and the Systematics computation works fine. However, when pdlabel is different to LHAPDF, e.g. pdlabel = nn23lo (or nn23lo1, nn23nlo, cteq6_m, etc.), then the Systematics computation fails.
In case I need to download and install manually the nn23lo, nn23nlo, etc. sets, would you be able to indicate how to do it?
Many thanks in advance for your patience.
Cheers,
Emilio.