Copy operations fail

[aj465]

I am finding that copy operations to and from my Netgear ReadyNAS are failing partway through. I get the message "Copy operation failed. The file or directory is not usable". The permissions should be OK, and a partial file is created at the destination.

Here are the logs from the console:

background.js:793 onWriteFileRequested
background.js:794 Object {data: ArrayBuffer, fileSystemId: "webdavfs:///https:///", offset: 125665280, openRequestId: 499, requestId: 750}
background.js:344 writeFile failed
background.js:345 ProgressEvent {total: 524288, loaded: 32768, lengthComputable: true, path: Array[0], cancelBubble: false…}
background.js:806 FAILED
background.js:701 onCloseFileRequested
extensions::lastError:133 Unchecked runtime.lastError while running fileSystemProviderInternal.operationRequestedSuccess: NOT_FOUND
at null. (chrome-extension://hmckflbfniicjijmdoffagjkpnjgbieh/background.js:803:17)
at null. (chrome-extension://hmckflbfniicjijmdoffagjkpnjgbieh/background.js:353:33)reportIfUnchecked @ extensions::lastError:133handleResponse @ extensions::sendRequest:79