Hadd huge number of root files?

Dear experts,
when I try to add about 10000 root file, at some point I have the error message [1]. Is it related to the high number of root file? Is there a limit on the number of root file when we want to add? If not, is there an option to avoid this problem?
Regards

[1]

hadd Opening the next 883 files
hadd Target path: DYJetsM50.root:/
hadd Target path: DYJetsM50.root:/h2taus
hadd Target path: DYJetsM50.root:/h2taus/sync
Error R__unzip_header: error in header
Info in TFileMerger::MergeRecursive: could not read object for key {nevt, Initial number of event}
Error R__unzip_header: error in header
Info in TFileMerger::MergeRecursive: could not read object for key {mt, mt}
Error R__unzip_header: error in header
Info in TFileMerger::MergeRecursive: could not read object for key {et, et}
Error R__unzip_header: error in header
Info in TFileMerger::MergeRecursive: could not read object for key {tt, tt}
Error R__unzip_header: error in header
Info in TFileMerger::MergeRecursive: could not read object for key {em, em}
hadd Target path: DYJetsM50.root:/h2taus/h2taus
Error R__unzip_header: error in header

hadd should not a limit on the number of input files. I will be looking at the problem.

Thanks,
Philippe.

Hi Pcanal,

this is great if you could fix this. Indeed I’m not the only person who experience trouble when merging huge root files. Also when I run on 100000000 evt I got all my jobs back successfully in 10000 output files, but when I merged them, event with very small number, at the end I have about 10000000 evt in the merged root file, so many evts is missing, and I do not have any error message which say what happened!

Regards