Mark Charles

``` Fatal Exception: java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Object.hashCode()' on a null object reference at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:772) at org.wlf.filedownloader.file_download.DownloadTaskManager.getRunningDownloadTask(DownloadTaskManager.java:183) at org.wlf.filedownloader.file_download.DownloadTaskManager.getRunningDownloadTask(DownloadTaskManager.java:166) at org.wlf.filedownloader.file_download.DownloadTaskManager.isDownloading(DownloadTaskManager.java:836) at org.wlf.filedownloader.file_download.DownloadTaskManager.notifyDownloadStatusFailed(DownloadTaskManager.java:434) at org.wlf.filedownloader.file_download.DownloadTaskManager.access$500(DownloadTaskManager.java:45) at org.wlf.filedownloader.file_download.DownloadTaskManager$5.onDetectUrlFileFailed(DownloadTaskManager.java:736)...