Cannot upload or share photos to Facebook since updating to Mohave

Prior to Mojave, there were two ways to get pictures directly from the Photos library to Facebook: push them from inside Photos to Facebook and pull them into Facebook from the Photos library. For reasons beyond the scope of these discussions, Apple removed the "push" method; only the "pull" method remains.

Here's the "pull" method for posting a picture:

Sign into Facebook in a browser (such as Safari).

Start a new post with the Photo/Video button.

When you get an Open dialog, scroll way down the left sidebar past Locations and Tags to the Media section.

Under Media, click on Photos. You should get a photo browser.

If you see multiple sources at top (such as Photos and Photo Booth), click Photos. (You might also want to expand Photos into Moments, Collections, etc. by clicking on the exposure triangle left of "Photos" and select one of those views.)

Wait for the contents of your Photos library (or view) to appear below the source list.

Select one or more of the photos or videos listed.

Click the "Choose" button.

Wait for it/them to load into the page.

Hover over the thumbnails to see options to edit them, remove them, or tag people.

Add text if needed.

Click "Post".