Android Question r file generation

[yasser123]

B4A Version : 8.50
Analyse du code. (0.00s)
Building folders structure. (0.03s)
Compilation du code. (0.03s)
Compilation du code des layouts. (0.00s)
Organiser les bibliothèques. (0.00s)
Génération du fichier R. Error
res\values-v20\theme.xml:3: error: Error retrieving parent for item: No resource found that matches the given name '@android:style/Theme.Material'.
how to solve this please

 

[Erel]

Follow the installation instructions: https://www.b4x.com/b4a.html
It will work.