Studies have shown that mobile apps are prone to crashes due to a network issue, mainly because successful network calls return unexpected or no data. And we found that when this app (version 0.4.5)'s network returned data is null or empty, the app has crashed. the specific crash information is as follows:

java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.e(Log.java:232)
at org.opengappsdownloader.Download.parseUrl(Download.java:100)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:67)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:63)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
... 4 more
java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.e(Log.java:232)
at org.opengappsdownloader.Download.parseUrl(Download.java:100)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:67)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:63)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)

Please remove the open source icon as this app doesn't deal with open source softwares.

Please, add more detailed documentation on what can be installed by this app.

Environment Info：
APK:android:versionCode="12" android:versionName="0.4.6"
AndroidOS Version = 6.0.1

Description information：
We find that mobile apps are prone to crashes due to a network issue, mainly because successful network API calls return unexpected or no data.
And we found that when this app's network returned data is null ，or the network request fails (status code is 404/503), the app has crashed.

crash information：
crash one:
crashActivity=org.opengappsdownloader.SetPreferenceActivity

:

java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:309)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)

Caused by: java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.e(Log.java:232)
at org.opengappsdownloader.Download.parseUrl(Download.java:108)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:76)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:72)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
... 4 more
java.lang.NullPointerException: println needs a message
at android.util.Log.println_native(Native Method)
at android.util.Log.e(Log.java:232)
at org.opengappsdownloader.Download.parseUrl(Download.java:108)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:76)
at org.opengappsdownloader.Download$ParseURL.doInBackground(Download.java:72)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)

Finally：
The cause of the program crash may be that the network response data is not handled properly in the code, such as null or empty.

If you have confirmed or fixed this problem, please give me a reply, thank you!

I simply installed it through F-Droid. Fire OS 4 6.6.1. It animates like it's about to launch, but just returns me to the screen I was at.

Not sure what other information I could provide that would help.