I am using QGIS version 3.8.3-Zanzibar I have a .shp file and I want to compute the area by using Vector/Geometry tool/Add Geometry attributes.

Runnig this tool I get :

Feature (11) has invalid geometry. Please fix the geometry or change the Processing setting to the "Ignore invalid input features" option. Execution failed after 0.06 seconds

Any suggestion how to solve this? Thank you