Share point office 365 Create a synchronized copy of the document library
What is SharePoint library Synchronization?
Description: SharePoint Document library synchronization is the process to sync the documents of the SharePoint library in to the local system. After sync the documents in to local system one can edit the documents in to local system it will automatically sync to SharePoint system.
This feature is very use full when one would like to edit / update files in to the local system & wants to permanently save in to the SharePoint system.
How to Enable Synchronization:
To Enable the SharePoint Library Sync process you need to follow below steps.
· Login as SharePoint Admin in to SharePoint Admin Portal.
· Select the App Launcher Icon 
this will display at the upper left.
· Go to the Admin centers -> SharePoint -> Settings
· Under the One Drive Sync Button tab please make sure that show the sync button option is selected.
How to Start Document Library Synchronization:
To start share point document library go to the document library settings
Click on Sync icon
At the prompt, click Sync Now to start the sync app wizard. The wizard automatically fills in the name and web address of the library
You can click Show my files… in the wizard to open the synced library in File Explorer. The folder is listed under Favourites, in the SharePoint folder
Read only problem while editing files in to the local system.
After Sync SharePoint files in to the local system & when any one start the Editing the files the read only problem occurs a message like a read only you have not sufficient permission to edit the files.
Why read only problem comes on Editing the files in to the local system?
The read only problem comes when some columns of the content type is mandatory. To enable editing change mandatory fields in to the non-mandatory.