I'd like to be able to upload to Facebook direct from Lightroom CC 2015 but I cannot get the Facebook plugin to authorise.
When I click the authorise buttton I get the message telling me to follow the prompts...but there are no prompts !!
Please follow the below link for the correct work flow.
Also, if you are using Lightroom 6 then you can try reset the Lightroom preferences.
"Press the shift + option keys immediately after you restart Lightroom, and select Reset Preferences from the resulting dialog box"
Let us know if that helps.