Steps to reproduce:
1) Setup elasticsearch using provided instruction from documentation (documentation)
2) Create mapping for UINT value
3) Create host with Agent trap item.
4) Create "Top hosts" widget, with column as "Item value" (use item created before).
5) Turn on server and agent.
6) Send few values to item.
7) Check Top hosts widget - everything looks ok.
8) Open widget edit form and change Aggregation function to min (or any NOT none).
9) Update and Apply. Now check Top hosts widget.

Result:

Expected:
No error, displayed correct values.

More info: Removing "global $DB, $HISTORY;" from zabbix.conf, there is no error, but values not displayed (if used Aggregation function any except none).