It stopped working after the call to arms update, it still seems to work for smaller blueprints but not larger ones, I did reach out to Marco on Discord, but so far no response .
But all is not lost, you can still create, save and place blueprints with the Infinity Hammer mod using the console commands 'Hammer_save filename' to save and place the blueprint using the command 'hammer_blueprint filename" after you create the blueprint by equiping the hammer and using the 3rd hammer from the left under the misc tab ,you cannot add snap points or terrain markers yet but I am told by the dev that they are coming soon. you can also do many other things that planbuild cannot as long as you don't mind using the console ;)
Hope this helps ....
