416 error always occurs when copying files from owncloud WebDAV to local

[onemouth]

HI, I use the plugin to mount owncloud WebDAV, but it always shows "operation taking longer than expected". when copying files from owncloud to local.
And logs shows 416(Requested Range Not Satisfiable) when the final GET operation finished.
It seems that the plugin try to read beyond the file size.

log:
onReadFileRequested - start
background.js:682 Object {fileSystemId: "webdavfs://lt.tsai/https://172.16.10.215/remote.php/webdav", length: 524288, offset: 0, openRequestId: 165, requestId: 167}
background.js:249 ArrayBuffer {}
background.js:690 Object {data: ArrayBuffer, hasMore: false}
background.js:681 onReadFileRequested - start
background.js:682 Object {fileSystemId: "webdavfs://lt.tsai/https://172.16.10.215/remote.php/webdav", length: 524288, offset: 524288, openRequestId: 165, requestId: 168}
background.js:249 ArrayBuffer {}
background.js:690 Object {data: ArrayBuffer, hasMore: false}
background.js:681 onReadFileRequested - start
background.js:682 Object {fileSystemId: "webdavfs://lt.tsai/https://172.16.10.215/remote.php/webdav", length: 524288, offset: 1048576, openRequestId: 165, requestId: 169}
background.js:249 ArrayBuffer {}
background.js:690 Object {data: ArrayBuffer, hasMore: false}data: ArrayBufferhasMore: false__proto__: Object
background.js:681 onReadFileRequested - start
background.js:682 Object {fileSystemId: "webdavfs://lt.tsai/https://172.16.10.215/remote.php/webdav", length: 524288, offset: 1180035, openRequestId: 165, requestId: 170}
background.js:465 GET https://172.16.10.215/remote.php/webdav//Product%20Spec/ArkEase%20Pro%20for%20Outlook%20Design-20150421.pptx 416 (Requested Range Not Satisfiable)send @ background.js:465m.extend.ajax @ background.js:4WebDavClient.readFile @ background.js:242WebDavFS.onReadFileRequested @ background.js:685(anonymous function) @ background.js:1012(anonymous function) @ background.js:977target.(anonymous function) @ extensions::SafeBuiltins:19EventImpl.dispatchToListener @ extensions::event_bindings:387target.(anonymous function) @ extensions::SafeBuiltins:19publicClass.(anonymous function) @ extensions::utils:94EventImpl.dispatch_ @ extensions::event_bindings:371dispatchArgs @ extensions::event_bindings:243(anonymous function) @ extensions::fileSystemProvider:208dispatchEvent @ extensions::event_bindings:250
background.js:412 Object {readyState: 4, status: 416, statusText: "Requested Range Not Satisfiable"}
background.js:690 ArrayBuffer {}
extensions::schemaUtils:113 Uncaught Error: Invocation of form fileSystemProviderInternal.readFileRequestedSuccess(string, integer, undefined, undefined, integer) doesn't match definition fileSystemProviderInternal.readFileRequestedSuccess(string fileSystemId, integer requestId, binary data, boolean hasMore, integer executionTime)normalizeArgumentsAndValidate @ extensions::schemaUtils:113(anonymous function) @ extensions::binding:374onSuccessCallback @ extensions::fileSystemProvider:199(anonymous function) @ background.js:691handleError @ background.js:417(anonymous function) @ background.js:255j @ background.js:2k.fireWith @ background.js:2x @ background.js:4(anonymous function) @ background.js:458
background.js:701 onCloseFileRequested