Issue when used in mendix v7.27

[Mocke44]

error in client :
obj.getGUID is not a function TypeError: obj.getGUID is not a function
at http://localhost:8080/widgets/DownloadMultipleFiles/widget/DownloadMultipleFiles.js?637175443783482410:68:103
at Object.forEach (http://localhost:8080/mxclientsystem/mxui/mxui.js?637175443783482410:5:30384)
at E..O._startDownload (http://localhost:8080/widgets/DownloadMultipleFiles/widget/DownloadMultipleFiles.js?637175443783482410:61:23)
at http://localhost:8080/mxclientsystem/mxui/mxui.js?637175443783482410:5:26619
at O (http://localhost:8080/mxclientsystem/mxui/mxui.js?637175443783482410:79:25829)
at http://localhost:8080/mxclientsystem/mxui/mxui.js?637175443783482410:79:31829