All packages are not available for download! The following packages are not available: - Package id sources;android-24
Am trying getting data from database by using of web services, when am running the application getting an above shown error.
How can I resolve this issue in the android studio?
The popup error is not related to the exception you got on your application. Api 24 source code is not fully available. Hence you got the error. Change complieSdkVersion and targetSdkVersion to 23 and sync the gradle.
Open SDK Manager -> SDK Platform
Check on Show Package Details and Sources for Android ... then download
Check if the SDK version is installed on Android studio for that particular Android device. e.g. If Android Device has version 4.3 then check if SDK for this version 4.3 is installed, you can check it through Android Studio SDK manager. If not installed then install it complete.
Restart Android studio, reconnect the device, That's it
A thing I ran into, check to see if you have more than one android sdk on your box. I'm not sure if it was confusing Android studio or not, but I had one previously installed under Program Files. I ended up going into the AppData\Local\Android version used by Android studio and adding stuff I needed manually running the SDK manager as administrator.
This means that you can't reach the download site, and it has many reasons one of them is that you are in a country in wich the American laws won't allow to use such technology so you have to use a proxy program and to configure the sitting in your Android studio to use the proxy gate and port.
I just closed my IDE then restarted my computer. When I opened the IDE the error was no more.
Make sure you have good internet connection, as the error might be caused by a lack of internet connection preventing the IDE from reaching the site.
来源：https://stackoverflow.com/questions/38714165/all-packages-are-not-available-for-download-error-in-android