When I call minioClient.puObject,I got this exception a few times.

io.minio.errors.ErrorResponseException: We encountered an internal error, please try again.
at io.minio.MinioClient.execute(MinioClient.java:1200) ~[minio-3.0.8.jar:3.0.8]
at io.minio.MinioClient.executePost(MinioClient.java:1347) ~[minio-3.0.8.jar:3.0.8]
at io.minio.MinioClient.initMultipartUpload(MinioClient.java:4276) ~[minio-3.0.8.jar:3.0.8]
at io.minio.MinioClient.putObject(MinioClient.java:3751) ~[minio-3.0.8.jar:3.0.8]
at io.minio.MinioClient.putObject(MinioClient.java:3380) ~[minio-3.0.8.jar:3.0.8]

This is the minio server logs

time="2017-12-01T09:38:53Z" level=error msg="Unable to initiate new multipart upload id." cause="mkdir /data/.minio.sys/multipart/writkeeper/2017/12/01: no such file or directory" source="[object-handlers.go:677:objectAPIHandlers.NewMultipartUploadHandler()]" stack="fs-v1-multipart.go:375:fsObjects.newMultipartUpload fs-v1-multipart.go:423:fsObjects.NewMultipartUpload :1:(*fsObjects).NewMultipartUpload object-handlers.go:675:objectAPIHandlers.NewMultipartUploadHandler api-router.go:55:(objectAPIHandlers).NewMultipartUploadHandler-fm"
time="2017-12-01T09:40:44Z" level=error msg="Unable to initiate new multipart upload id." cause="mkdir /data/.minio.sys/multipart/writkeeper/2017/12/01/tpl/basetpl: no such file or directory" source="[object-handlers.go:677:objectAPIHandlers.NewMultipartUploadHandler()]" stack="fs-v1-multipart.go:375:fsObjects.newMultipartUpload fs-v1-multipart.go:423:fsObjects.NewMultipartUpload :1:(*fsObjects).NewMultipartUpload object-handlers.go:675:objectAPIHandlers.NewMultipartUploadHandler api-router.go:55:(objectAPIHandlers).NewMultipartUploadHandler-fm"
time="2017-12-01T09:41:32Z" level=error msg="Unable to initiate new multipart upload id." cause="mkdir /data/.minio.sys/multipart/writkeeper/2017/12: no such file or directory" source="[object-handlers.go:677:objectAPIHandlers.NewMultipartUploadHandler()]" stack="fs-v1-multipart.go:375:fsObjects.newMultipartUpload fs-v1-multipart.go:423:fsObjects.NewMultipartUpload :1:(*fsObjects).NewMultipartUpload object-handlers.go:675:objectAPIHandlers.NewMultipartUploadHandler api-router.go:55:(objectAPIHandlers).NewMultipartUploadHandler-fm"

My enviroment

Minio Server

1. Linux version 4.12.8-1.el7.elrepo.x86_64 (mockbuild@Build64R7) (gcc version 4.8.5 20150623 (Red Hat 4.8.5-16) (GCC) ) Full restructure in accordance with #1 SMP Thu Aug 17 09:11:11 EDT 2017
2. Minio Server docker version 2017-11-22T19:55:46Z

Minio Client

1. Minio Java Client 3.0.8