Hello and sorry. Shoulf have really provided more informations but it was late for me. There are multiple peers involved. But basicly it is 1 master-server which has the read-write access and all other peers have read-only. The master-server is Linux, most other peers are Windows or Linux. Which is possibly important is that i use the selective sync feature for all windows peers so it is not necessary to sync all folders from the master-server. I waitet quite some time (not exactly sure how long but i would say it should have been able to create the folders) The whole application purpose is an updater tool so all other peers should never be able to make changes on the sync folder. But it is of course possible that they delete some folder and after that BTSync seems not to recreate them at the next sync. For the moment i create all folders and subfolders from my application with the help of the get_files method and it works very good. But i wonder if btsync shouldnt create them.