Can I use Columns any more?
Since the free demo of Stacks is more capable than even the payed-for version of Columns, it didn't feel right taking money for it any longer. So it's been discontinued and we'd recommend not using it if you can avoid it.
It's very likely that in the next version of RapidWeaver, Columns will stop working. It's code from our very first RapidWeaver releases that dates all the way back to 2005. It's been updated a few times, but is by-and-large unchanged.
We recommend that you move over to Stacks, when you have the chance. You can just copy and paste you existing content into two text Stacks and get very similar results. It's really easy to put together a two column layout in Stacks. And configuring it is much easier than it ever was in Columns. And even if you don't own Stacks, the free demo can do two columns even in the free demo mode.
If you have an existing project that still uses Columns and you need a copy of the old plugin, you can download it from the Plugin Archive.