UserAgent: Mozilla/5.0 (X11; CrOS x86_64 11215.0.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3605.0 Safari/537.36
Platform: 11215.0.0 (Official Build) dev-channel chell test 

Steps to reproduce the problem:
1. Plug Pixel phone into Chromebook and enable "File Transfer" mode on the phone
2. Open Files app
3. Copy some files to a directory on the phone

What is the expected behavior?
Files are copies.

What went wrong?
Files app hangs part-way during copy, then fails. Phone is then no longer accessible until it is unplugged and re-plugged. Deleting files also causes the same failure.

Did this work before? N/A 

Chrome version: 72.0.3605.0  Channel: n/a
OS Version: 11215.0.0
Flash Version: 

/var/log/messages:
2018-11-13T10:47:50.966362+11:00 ERR mtpd[1521]: CopyFileFromLocal(...): Domain=dbus, Code=org.chromium.Mtpd.Error, Message=CopyFileFromLocal failed
2018-11-13T10:48:41.201640+11:00 ERR shill[1223]: [ERROR:dhcp_config.cc(274)] Timed out waiting for DHCP lease on eth0 (after 30 seconds).
2018-11-13T10:48:51.017309+11:00 ERR mtpd[1521]: ReadDirectoryEntryIds(...): Domain=dbus, Code=org.chromium.Mtpd.Error, Message=ReadDirectoryEntryIds failed
2018-11-13T10:49:41.209172+11:00 ERR shill[1223]: [ERROR:dhcp_config.cc(274)] Timed out waiting for DHCP lease on eth0 (after 30 seconds).
2018-11-13T10:49:51.020479+11:00 ERR mtpd[1521]: ReadDirectoryEntryIds(...): Domain=dbus, Code=org.chromium.Mtpd.Error, Message=ReadDirectoryEntryIds failed
2018-11-13T10:50:41.211988+11:00 ERR shill[1223]: [ERROR:dhcp_config.cc(274)] Timed out waiting for DHCP lease on eth0 (after 30 seconds).
2018-11-13T10:50:51.023448+11:00 ERR mtpd[1521]: ReadDirectoryEntryIds(...): Domain=dbus, Code=org.chromium.Mtpd.Error, Message=ReadDirectoryEntryIds failed
2018-11-13T10:51:28.308892+11:00 DEBUG kernel: [859406.073576] SELinux: initialized (dev proc, type proc), uses genfs_contexts

~/log/chrome:
[30879:30903:1113/104550.307641:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.383191:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.458352:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.492639:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.532145:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.617937:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.663012:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.707542:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.746236:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.822609:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
[30879:30903:1113/104550.933217:ERROR:device_media_async_file_util.cc(409)] Not implemented reached in virtual void DeviceMediaAsyncFileUtil::Touch(std::unique_ptr<FileSystemOperationContext>, const storage::FileSystemURL &, const base::Time &, const base::Time &, storage::AsyncFileUtil::StatusCallback)
...
[30879:30879:1113/104816.018322:ERROR:object_proxy.cc(621)] Failed to call method: org.chromium.Mtpd.ReadDirectoryEntryIds: object_path= /org/chromium/Mtpd: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
[30879:30903:1113/104816.018802:INFO:mtp_device_delegate_impl_chromeos.cc(1886)] Check failed: !it->second->HasChildren(). 
[30879:30903:1113/104816.018912:INFO:mtp_device_delegate_impl_chromeos.cc(505)] Check failed: !it->second->HasChildren(). 
[30879:30879:1113/104841.032284:ERROR:object_proxy.cc(621)] Failed to call method: org.chromium.Mtpd.GetFileInfo: object_path= /org/chromium/Mtpd: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
[30879:30903:1113/104841.032755:INFO:mtp_device_delegate_impl_chromeos.cc(1886)] Check failed: !it->second->HasChildren().