Appdaemon test dashboard won't display my switches and other widgets anymore

Hi fellows

I managed several months ago to create a light dashboard just to be able to have some remote switch for my living room’s lights.
Last time i use it, a few month while, it was running sweet,but it was still a work in progress and i forgot it since…
Now, i have the time to finish the work, so i just opened my test dashboard, but the switch aren’t displayed anymore. Only empty cells with the widget title.
It’s as if the entities weren’t existing anymore. But they are still completely functional and working in HAdashboard ?

Any help would be glaldy appreciate to help me understand what is going wrong, and sorry for my english as it’s not my native language.

Please post the dashboard file so we can have a look. Did you set any custom icons for the widgets?