Error when making an MyElectric app

On my emonpi, when I cry to create an app for electricity monitoring I got this error:

EmonCMS Error
-------------
Message: TypeError: datastore[name].data[0] is undefined
Route: Modules/app/Lib/timeseries.js?v=25
Line: 18
Column: 9

it’s on a emonpi directly from EmonCMS.org.

Components: Emoncms Core v11.3.0 | App v2.6.10 | EmonHub Config v2.1.5 | Dashboard v2.3.3 | Device v2.2.2 | Graph v2.2.3 | Network Setup v1.0.2 | WiFi v2.1.1 | Backup v2.3.2 | Postprocess v2.2.7 | Sync v2.1.4 | Usefulscripts v2.3.10 | EmonScripts v1.6.7 | RFM2Pi v1.4.1 | Avrdude-rpi v1.0.1 | Emonhub v2.5.5 | EmonPi v2.9.5