Problems with merging outputs

Dear experts,
my jobs on proof are stuck at the 99.6% and don’t start the merging the outputs.
This happens only when running on 200k events, but not on 50k events.
I’m using 16 worker nodes.
Could you please give me an advice?
Best regards,

Dear Marianna,

What kind of objects do you have in your output file? Do you expect them to grow in size with increasing number of entries (e.g. trees) or stay constant (e.g. histos)?
Could you also specify the ROOT version you are using?

G Ganis