Status is OK when drive has failed

Get the following error when a drive has failed

Argument “–” isn’t numeric in numeric lt (2, Disk1:ready, Disk2:ready, max. Temperature:37C
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Disk 1 Status: ready, SmartInfo: GOOD, Typ: WD20EARS-00MVWB0, Size: 1.82 TB, Temp: 37 C/98 F
Disk 2 Status: ready, SmartInfo: –, Typ: ST2000DM001-9YN1, Size: 1.82 TB, Temp: — C/– F