downloadURL throwing a exception Operation Not Permitted

Dear Greg,

I am running exactly in the same problem. It works for us on iPad with iOS 9.3.5 and iOS 10.2 but it fails with the follwong message on a iPad Pro 12.9" with iOS 10.3 (and I made a pod update this moring to version 3.0.10):

NSError = "Error Domain=NSCocoaErrorDomain Code=513 \"\U201eCFNetworkDownload_usQ10T.tmp\U201c konnte nicht bewegt werden, da du nicht \U00fcber die erforderlichen Zugriffsrechte f\U00fcr \U201etmp\U201c verf\U00fcgst.\" UserInfo={NSSourceFilePathErrorKey=/var/mobile/Library/Caches/com.apple.nsurlsessiond/Downloads/com.-----.——/CFNetworkDownload_usQ10T.tmp, NSUserStringVariant=(\n    Move\n), NSDestinationFilePath=/private/var/mobile/Containers/Data/Application/03757827-B45C-4CFD-9F34-DFE20371E541/tmp/Pepsi.jpg, NSFilePath=/var/mobile/Library/Caches/com.apple.nsurlsessiond/Downloads/com.-----.-----/CFNetworkDownload_usQ10T.tmp, NSUnderlyingError=0x17045a340 {Error Domain=NSPOSIXErrorDomain Code=1 \"Operation not permitted\"}}"

I implemented also the proposals with the "sharedContainerIdentifier" from your referring link (https://github.com/dropbox/dropbox-sdk-obj-c/issues/60) but I does not solve the problem:

    DBTransportDefaultConfig *transportConfiguration = [[DBTransportDefaultConfig alloc] initWithAppKey:DROPBOX_APP_KEY
                                                                                              appSecret:DROPBOX_APP_SECRET
                                                                                              userAgent:nil
                                                                                             asMemberId:nil
                                                                                          delegateQueue:nil
                                                                                 forceForegroundSession:NO
                                                                              sharedContainerIdentifier:[NSBundle mainBundle].bundleIdentifier];
    [DBClientsManager setupWithTransportConfig:transportConfiguration];

Should I open a separate issue for that on Github?