WD Sync not uploading files to drive

I have a WD My Cloud and installed WD Sync in my laptop which operates with Windows 10.

The sync folder I have create is only able to retreive files from the drive my laptop (I upload them directly via the web site). If I create a file in the folder on the laptop, WD sync is unable to send it to the drive and keeps sending this message:

Can I be doing something wrong?

What type of file are you trying to send. The following is from the WD My Cloud User Manual.

WARNING! The WD Sync software is designed for data files. It is neither intended
nor suitable for syncing your applications or executable program

Here is the link for the User Manual.


Thank you cat0w for your reply but the problem is not the type of file.
I’m only able to upload to the drive if I am in the same network.