I took a bunch of trees and put them into a group, which turned them into a model. Then I created a script and tried to anchor them, it said there was a problem. Unknown global 'anchored' please help. My script is, "local Trees = game.Workspace.Trees
Anchored.Trees = true"
This is more of a studio problem than a scripting problem. I suggest that you use the built in feature for anchoring multiple parts in studio. You can find the button next to the Color and Material buttons at the top of the screen. Or alternatively you could use the shortcut Alt+A, which does the same thing.
local Model=workspace.Model for _,v in ipairs(Model:GetDescendants())do if v:IsA"BasePart"then v.Anchored=true;end end