On 6 Jul 2018, at 11.42, Timo Sirainen <tss@iki.fi> wrote:

On 6 Jul 2018, at 1.53, Martynas Bendorius <martynas@martynas.it> wrote:

Dovecot 2.3.2 still has the same issue we reported for 2.3.X:

Jul 05 15:10:49 lmtp(2730445): Panic: file lib-event.c: line 182 (event_pop_global): assertion failed: (event != NULL)
...
#5  0x00007f6502986e42 in event_pop_global (event=<optimized out>) at lib-event.c:182
      __func__ = "event_pop_global"
#6  0x00007f6502c68f88 in mail_storage_service_io_deactivate_user_cb (user=0x7f65048e4708)
  at mail-storage-service.c:823
---Type <return> to continue, or q <return> to quit---
      event = 0x0
      __func__ = "mail_storage_service_io_deactivate_user_cb"

Could you also run in gdb:

fr 6
p *user
p *user->pool

Also what's your doveconf -n?

Also, does this happen to fix it? https://github.com/dovecot/core/commit/231865af423b4fa4da209a0721de57840c9b91de.patch