We found attributes on some of your Active Directory user accounts that have unsupported characters or are too long. You ...

We found attributes on some of your Active Directory user accounts that have unsupported characters or are too long. You have to fix those attributes before you can use Directory Synchronization. You can see a list of these users by opening Windows explorer and reviewing the files in folder Office365logs on your computer. Click on the link 'get help fixing this issue' in the actions pane located on the right side of the screen for assistance.