Hey @Vitor_Alano! Welcome to the community. 
We've had a few different reports of this pop up this morning:
- List View / Grid View not showing anything when placed inside of a container - #7 by Tess
- Bug Displaying ListViews (Not Showing Anything) - #2 by Darren
The quick fix for now is to disable WidgetGrid but we should have a more permanent solution rolling out soon!