Removing element set breaks contribution plugin

I’ve now managed to break the contribution plugin twice, with no discernible fix. To replicate:

  1. Install Omeka Classic
  2. Install the Contribution plugin and an alternative metadata set (in my case VRA Core)
  3. Add a contribution under contribution types. Note the metadata fields filter nicely into Dublin Core and VRA Core.
  4. Remove the VRA Core Element Set in Settings
  5. Reinstall the VRA Core plugin
  6. Go back to the Contribution Types and try adding a new element. Note how there are now multiple choices for some of the same metadata elements (see attached). Choosing the wrong one breaks the public contribution side, and effectively users cannot contribute any items.

I have no idea how to fix this, or even why this would break core Omeka functionality!

There’s a setting for whether to show those element set labels in the element dropdown: it’s controlled by the “Show Element Set Headings” setting in Appearance -> Settings.

That’s it! Strangely this setting also affects the front end in that it displays the element set name at the top of item metadata, which is not desired. Our workaround for now is to turn it on when we want to edit the configuration settings and turn it off all other times.

I have a further question about this: In this same scenario, if I choose a VRA metadata element to map a contribution to it breaks the contribution form. When a user on the public side tries to select a contribution type that is set to VRA, nothing displays when the contribution type is selected. However if all the elements are Dublin Core it works as expected. Is this anticipated behavior? Is there a way to map a contribution to VRA?