thank you for your fast and precise reply!
I tried to check where the information starts to miss; but it seems it is a common feature of all the variables still from the beginning of the analysis.
For example if I take the processor
processor Frs/Scintillators/dEnergySc21 UTILS.Pair
first <- FrsCrate.qdc1
second <- FrsCrate.qdc1
which simply takes the "raw" values from the Frs Crate for Sc21 (but it is the same for Sc41 for example) and plots them I already see that that the "Frs_Scintillators_dEnergySc21__first_valid" variable is 0 90% of the time.
Since FRS scintillators are the "fastest" detectors we have I did not expect to have such a large amount of invalid events in them.
Moreover it seems that these events are invalid already when they come out from the Frs Crate; this is what I don't understand. What does it mean that raw values from the Crate are invalid?
Thank you very much, and sorry for bothering you!!