If you need to use labels longer than 10 inches, the WPL610 will not calibrate them by default. To allow the longer labels, download and extract:
https://dl.waspbarcode.com/kb/printer/wpl6xx/WPL610LongLabels.zip
Run DiagTool_151.exe, then switch to the Command Tool tab. Click Send File and select the WPL610-12.TCF file and send it. When it finishes, the printer will reset and you should be able to perform the calibration.