pythonThresholdException User-supplied Python expression

Hi,

I am using Zenoss Core verson 3 and having below error on some window devices performance graph.

The server reported the following error:

pythonThresholdException User-supplied Python expression (here.getRRDValue('MemoryTotal') * 0.8) for maximum value caused error: ['Memory_MemoryUsed']

The system has encountered an error. Please reload the page.

Note:

I am using ZenPacks.Nova.Windows.SNMPPerfMonitorSimple 1.6 for performance graphs (CPU and Memory).

Error snap shot is also attached for the reference.

Kindly guide.

Regards,

Arshad