Display error when use zabbix datasource

[tomcsi]

If I use zabbix datasource, all works perfectly, but all of time refreshing the page then display the error dialog top right.

Error message: Cannot read property 'to' of undefined

Environment:

• Grafana version: 8.1.1
• flant-statusmap-panel version: 0.4.1
• Data source type & version: Zabbix 4.2.1
• OS Grafana is installed on: Ubuntu 16.04
• User OS & Browser: MacOS & Chrome latest

[headfox23]

With the last update of grafana to Grafana v8.1.1 (a10d7f91d3) we get exactly the same error message:

We dont use zabbix. We use prometheus...

[diafour]

See #219