Why cant i upload photos from my photo library

Make sure your library is designated the System Photo Library in Photos' General preference pane.

Also are you running "managed" or "referenced" library?

Also where is the library located? If on an EHD how is that drive formatted and connected to your Mac?

Are you able to see the photo in your library? If so a quick workaround is to export it to the Desktop and upload from there.

That means it already is the system photo library

As Terence said being greyed out means it is the System Photo Library already.

What is the problem? Why do you think there might be a problem with the System Photo Library?

Does something not work as expected?

Up load to where?