Crash Please Fix or Tell

[TheEngineerz]

This is my code which i am using for downloading

[[TWRDownloadManager sharedManager] downloadFileForURL:thumbURL.description withName:thumbURL.lastPathComponent inDirectoryNamed:@"Documents" progressBlock:^(CGFloat progress) {
NSLog(@"progress %f",progress);
} completionBlock:^(BOOL completed) {
NSLog(@"completed : %d",completed);
} enableBackgroundMode:YES];

But it is crashing on this line

    destinationLocation = [[self cachesDirectoryUrlPath] URLByAppendingPathComponent:download.fileName];

because i am getting nil "downloads" variable

TWRDownloadObject *download = [self.downloads objectForKey:fileIdentifier];

Following is the crash report

Download finisehd! file:///private/var/mobile/Containers/Data/Application/9B7CF0E4-B780-4EA4-A58F-456DA4C46165/Library/Caches/com.apple.nsurlsessiond/Downloads/com.company.aaaaa/CFNetworkDownload_oKSwT0.tmp
2015-07-14 16:56:12.730 aaaaa[331:32734] * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[NSURL URLByAppendingPathComponent:]: component, components, or pathExtension cannot be nil.'
*** First throw call stack:
(0x24802137 0x32b58c77 0x2480207d 0x254b3259 0x1d8263 0x2430d8c9 0x2552b439 0x254960a1 0x25488b0d 0x2552dd93 0x462d89 0x45cac5 0x464b1b 0x465e21 0x3326ada9 0x3326aafc)
libc++abi.dylib: terminating with uncaught exception of type NSException

[eni9889]

I am experiencing the same crash

[john916zhang]

same crash here.

[sunil-zalavadiya]

same crash here. Any update? It's happening while i am trying to download multiple files at a time.