About "Error drawing graph"

Hi,
I have some error drawing graphs.
I checked other posts but wasn’t helpful. Please assist or give me some suggestions.
Thanks!!

====================================

Component | Version

--------- | -------

LibreNMS | 1.61-43-gdf16de9d2

DB Schema | 2020_02_10_223323_create_alert_location_map_table (159)

PHP | 7.2.24-0ubuntu0.18.04.3

MySQL | 10.1.44-MariaDB-0ubuntu0.18.04.1

RRDTool | 1.7.0

SNMP | NET-SNMP 5.7.3

====================================

[OK] Composer Version: 1.10.1

[OK] Dependencies up-to-date.

[OK] Database connection successful

[OK] Database schema correct

There are some graphs like this: