Use the Root!
When configuring a SkySync connector it is best practice to create the connection at the "Root" or "Top" level and not at a sublevel.
For example, suppose a Network Share is structured as: \\server\ShareName\employee\Personal Folder\
When configuring the Network Share connector, the UNC path to the server should be: \\server\ShareName
After the connector has been created, the Sync Job source or destination is defined at the subfolder level of the share, as shown in the picture below.
To illustrate the issue, I have created a connector that points directly to a subfolder. The screenshot below illustrates the failure you will receive: