问创建UploadManager实例异常，求解？

mFileUploadManager = new UploadManager(context, appId, FileType.File, null);java.lang.NullPointerException at com.tencent.upload.log.trace.TracerConfig.getLogFilePre(Unknown Source) at com.tencent.upload.log.trace.a.b(Unknown Source) at com.tencent.upload.log.trace.a.c(Unknown Source) at com.tencent.upload.log.trace.a.<init>(Unknown Source) at com.tencent.upload.log.c.<init>(Unknown Source) at com.tencent.upload.log.b.a(Unknown Source) at com.tencent.upload.common.Global.init(Unknown Source) at com.tencent.upload.UploadManager.<init>(Unknown Source)