this issue is linked with https://github.com/piwik/piwik/issues/12014 (the second issue listed in is not fixed).
when I use widgetized dashboards, there is a link to my dashbord.
this link is following:
When I follow this link, there is an issue and I have only
[object Object] displayed.
Which version of Piwik are you using?
I use the latest one (3.1.1)
Can be reproduced here: https://demo.piwik.org/index.php?module=Widgetize&action=iframe&moduleToWidgetize=Dashboard&actionToWidgetize=index&idSite=3&period=week&date=today&token_auth=anonymous&updated=5&segment=deviceType%3D%3DSmartphone%2CdeviceType%3D%3DTablet
Thanks for the report @vincent3569