Wanted to duplicate a rigify rig to slightly modify it and add it to another character but now it won´t generate a rig

Question

I had a character which I rigged with Rigify (did some alterations to the standard Rigify rig), and wanted to duplicate it (Shift + D), and change the arm position for a character of equal build that had a different idle pose (The first one wasn't a t-pose which was a big oopsies from my part).

Unfortunately, when I try to generate the rig the button states "Re-generate rig" even though I hadn't generated a rig with the duplicated rig, and it doesn't allow me to generate the control rig, I get the error Target Rig Not Visible. Anyone knows how to fix this?

And what's the best way forward of duplicated previously used Rigify rigs?

Answer 1

When you generate a rig with Rigify, it can either create new assets or update existing ones.

By default, when you generate for the first time in a blender scene, it will create a new rig, Rig UI script and Widgets. After that first generation, any time your hit the generate button, it updates the existing assets.

When you duplicate a metarig and want to create a new rig, you have to tell Rigify to do so. Otherwise, it will keep updating the other rig.
Here you get the error Target Rig Not Visible because you moved the previous rig into a disabled collection, hence it can't access it and throws the error.

If you select the new metarig and look into Properties Editor > Armature Data tab > Rigify Panel > Advanced Sub-Panel:

You can see here that the new metarig is still set up to overwrite the old rig.

Click the X icons at the end of the names of the Target Rig, Rig UI script and Widgets Collection (though that one can be left as is if you just create regular rigs with the same widgets, to save memory).
You can even give your future rig a name.

Notice as well that, when you have no target rig, the button change from "Re-Generate Rig" to "Generate Rig". You can click it, and it will create a new rig.