merge tickets not working

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Hi all,

sorry for asking here but maybe this is the right place in the end.

If I merge tickets of which some are "blocked", "nothing" happens.
(I would expect something like "Sorry, you must be the owner of the tickts in order to performe that" action.)
But tickets are _not_ merged and I don't get any error.

The logfiles I can see only " -e: Use of uninitialized value $EmailArticleID in hash element at /opt/otrs//Kernel/Modules/AgentTicketBulk.pm line 562.

Could you give a hint?

Best,
Screenshot