Nextcloud Windows client / first sync failed whith "impossible to open directory" error message


We currently encountered a first sync failure with the Nextcloud Windows client. The sync client failed (after already uploading several GB of datas) with this message “impossible to open directory”

We got nothing on the server logs files (no Apache error and no PHP error)

We got this on the client side log (after pressing F12 key) :

OCC::AbstractNetworkJob::slotTimeout: virtual void OCC::AbstractNetworkJob::slotTimeout() OCC::LsColJob(0xc31bc20) Timeout QUrl(“”)
OCC::DiscoveryJob::remote_vio_opendir_hook: OCC::DiscoveryJob(0xd543320) /directory0/directory1/directory2/directory3/directory4/directory5 …Returned from main thread
OCC::DiscoveryJob::remote_vio_opendir_hook: 5 when opening /directory0/directory1/directory2/directory3/directory4/directory5 msg= “L’opération est annulée”
csync_ftw: opendir failed for /directory0/directory1/directory2/directory3/directory4/directory5 - errno 5

It’s really strange because the sync not always (but often) stuck on the same directory (after relaunching a sync process) … We have checked the content and the rights on these directories and all seem to be ok.

Our config :

  • server : Nexcloud 14.01 / Ubuntu 16.04LTS / Apache 2.4.18 / PHP PHP 7.0.32
  • client : Nextcloud Windows Client / Windows 2012 Server

Any ideas ?

Thanks in advance for your help !