B4X is a set of simple and powerful cross platform RAD tools:

B4A (free) - Android development

B4J (free) - Desktop and Server development

B4i - iOS development

B4R (free) - Arduino, ESP8266 and ESP32 development

All developers, with any skill level, are welcome to join the B4X community .

Android Question java.io.FileNotFoundException: /storage/emulated/0/file.xlsx: open failed: EPERM (Operation not permitted)

java.io.FileNotFoundException: /storage/emulated/0/file.xlsx: open failed: EPERM (Operation not permitted)
    at libcore.io.IoBridge.open(IoBridge.java:492)
    at java.io.FileOutputStream.<init>(FileOutputStream.java:236)
    at anywheresoftware.b4a.objects.streams.File.OpenOutput(File.java:449)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:348)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
    at java.lang.reflect.Method.invoke(Native Method)

Log(j.Tag) Log(j.GetString) Dim out As OutputStream = File.OpenOutput(File.DirRootExternal, FileName, False) File.Copy2(j.GetInputStream, out) out.Close Dim rerror As String Log("Error: " & j.ErrorMessage) rerror="Error: " & j.ErrorMessage rerror=rerror.Length Log(rerror) MsgboxAsync("Please connect to internet","Message") Return End If j.Release You don't give permission to access the File.Dirinternal. You need permission to File.DirRootExternal,. There are tons of threads dealing with this complex problem.
It is a permission problem.Start here and drill down to more links after that.