[android] AndroidStudio SDK directory does not exists

Right click your project and select 'Open Module Settings' under SDK Location put your location for your SDK.

paste in /Users/AhmadMusa/Library/Android/sdk

Clean and rebuild your project

Update

Try to delete your local.properties file and create a new one, but do not check it into version control.

Right click top level of project and Create new file 'local.properties' then add: sdk.dir=/Users/AhmadMusa/Library/Android/sdk

Clean and build