how did they get added in the 1st place?

I've never seen this either and can't reproduce. Can you give us more details please? See Contributing Bug Reports.

Specifically, what version of Phabricator are you on? There has been a lot of churn on Workboards this week, and even today. Does this bug exist at HEAD?

I just updated code early in the day, like 2am.

We expect people to update Phabricator before filing a bug report. We fix bugs very quickly. Even if you just updated a few hours ago, it's helpful for us to not have to spend time hunting down a bug that was already fixed.

This mostly applies to if you're following master. stable is only updated once a week.

Currently, it's hard from me to tell what's going on in the screenshot. Can you give us any more details on the setup?

• Is this a Workboard on a Subproject or Milestone?
• Did someone set up the Workboard manually, or import from another project?
• Are there any error messages in the web server log?
• Knowing you're at HEAD is helpful, we have resolved some bugs in this today.

These are sub projects imported from another project. But they never existed before when I originally imported their workboards. So I was as confused as you to how they suddenly started showing up.

In T10346#159072, @robertkraig wrote:

they never existed before when I originally imported their workboards

This clue was critical in finding the bug, which was related to the import process. Please provide as much information as you can when reporting issues!

At HEAD:

• Importing columns from a project with subprojects/workboards should no longer create empty columns.
• Empty columns can now be hidden.

Wow. This is awesome. I'm glad you were able to find and trace down this issue with what minimal info I could provide. I'll try to give better descriptions in the future. It would also be nice to remove columns that have no tickets associated with them.

I had to rename all those junk records just so I could hide them after the fact.