Steps:
1. Change Temp folder to different drive (USB stick works just fine. How to: https://answers.microsoft.com/en-us/windows/forum/windows_7-files/change-location-of-temp-files-folder-to-another/19f13330-dde1-404c-aa27-a76c0b450818?auth=1)
2. Have Unity 5.6 installed with Facebook package
3. Update to 2017.1
4. Create a New project

Result:
Error in the Console:
SDKUpdater failed: stdout:
[UpdateSupportedSDKList] Download <https://www.facebook.com/unitysdk/available_versions?unity_version=2017.1.1f1>
[UpdateSupportedSDKList] Received <{
"versions": [
"7.9.4",
"7.10.1"
]
}> to <C:\ProgramData\Unity/Facebook\SupportedSDKVersions\2017.1.1f1>
[UpdateAvailableSDKs] Download https://www.facebook.com/unitysdk/download?sdk_version=7.10.1 to T:\Temp\tmp534E.tmp
stderr:
Unhandled sdkuploader error: System.IO.IOException: Le chemin d'acc�s source et celui de destination doivent avoir des racines identiques. Le d�placement n'est pas possible entre ces volumes.
� System.IO.Directory.Move(String sourceDirName, String destDirName)
� SDKUpdater.UpdateAvailableSDKs()
� SDKUpdater.Main()

System.Threading.RegisteredWaitHandle:DoCallBack(Object)

Reproduced with: update from 5.6.3p4 to 2017.1.1p4