Could not save the document to the repository for the following reason

While schedule the reports because of the below reason some time report instance are getting fail.is there any solution for that,

Could not save the document to the repository for the following reason: [repo_proxy 30] InfoStore::ObjectExport::commit - (Helpers::InfoStore::ObjectExport::commit) File Repository Server error : Failed to put the file to file server: frs://Output/a_242/027/084/5512178/aduu8vtfkntmvyv8lsnntas.wid already exists.(hr=#0x80042a4a)(Error #-2147210678 (WIS 30567)

May i know why this error is occurring,If any one knows about this pls let me know.

Thanks.