Linked Accounts

My apologies.  My first post is pretty jumbled.  I have a lot of programming experience, but none of it on Android.  Until now. :)

I believe the version I am running is 3.0.0, and when I drop 3.1.2 in, the call to getInstance() never returns and never throws an exception.

I understand the Sync SDK is now deprecated, but I need to get this  application back up and running quickly.  I've been playing around some more and have some more details.

The problem seemingly related to specific versions on Android as I have an APK which will run on 4.4, 5.0.2, 5.1.1 and 6 on different Nexus 7's, but the same APK will also *not* run on Nexus 7's running the same.

I unboxed two identical Nexus 7's and set them up from scratch exactly the same, to 5.1.1 and ran the APK on both of them.  After choosing which Dropobx account to link to (I chose the same account on both) the application would crash.

I believe something else is happening though.  At first sight I was quite sure the problem was with the code I posted.  The actual code (not mine) is posted below.

The FileLoader class extends AsyncTask, and I believe the main error is an uncaught exception in doInBackground().

From looking through the forums there is something similar to what I'm getting, especially the mkdir issue, which is apparently fixed with 3.1.2 installed, which doesn't work for me.

https://www.dropboxforum.com/hc/en-us/community/posts/203290225-Error-from-DbxFileSystem-forAccount-init-cpp-201-mkdir-dV-files-No-such-file-or-directory 

Any help would be greatly appreciated.  Oh, and thanks for taking the time to read my ramblings.

public final static String SETTINGS_LOCATION = "/sdcard/etl_civ_settings.conf";
public final static String SETTINGS_UPDATE_LOCATION = "/etl_civ_settings.txt";

private FileLoader fl = null;
private DbxFileSystem fs;
private DbxAccountManager mgr;
private static final int REQUEST_LINK_TO_DBX = 0; 
private Activity act;

 act = this;
 mgr = DbxAccountManager.getInstance(this.getApplicationContext(), appKey, appSecret);

 if(!mgr.hasLinkedAccount()){
 mgr.startLink((Activity)this, REQUEST_LINK_TO_DBX);
 } else {
 
fl = new FileLoader(SettingsHandeler.SETTINGS_LOCATION,SettingsHandeler.SETTINGS_UPDATE_LOCATION, mgr, this);
 fl.execute(new String[] {});
 
 try {
 fs = DbxFileSystem.forAccount(mgr.getLinkedAccount());
 fs.addPathListener(this, DbxPath.ROOT, DbxFileSystem.PathListener.Mode.PATH_OR_CHILD);
} catch (Unauthorized e1) {
 // TODO Auto-generated catch block
 e1.printStackTrace();
}

 }