Screen Sharing won't allow me to paste into remote system

Apple answer: https://support.apple.com/kb/PH14152

Choose Edit >Use Shared Clipboard. Using the shared clipboard, you can:

Copy text and images from documents on one Mac and paste them into documents on the other.

Select and drag text and images from one Mac to the other.

Copy a link from your web browser and paste it into a web browser on the other Mac.

Copy text from a document on one Mac and drop it on the desktop of the other Mac to create a clipping.

I just disconnected my screen sharing session and re-connected and the copy/paste started working again.