I'm following a tutorial for Facebook login with Firebase, I will not put all the files because they are basically those of the tutorial itself.
When you run the code, the following error appears:
String types not allowed (at 'activity_horizontal_margin' with value ").
And when you click on the error, it goes to line 698 of the values.xml file :
<style name="Base.TextAppearance.AppCompat.SearchResult" parent="">
Should I have something between the quotation marks?
Print error and part of code: