Hello,
I have created a customized Content Type Document Set called OnBoard_A, the objective is that each item will be in fact a Folder(Container) where I can upload document on it.
Then I've created a customized form , no big deal, just a column Title , but when I try to use it in Sharepoint I get an error:

I wonder if I can use customized form Sharepoint with Document Library which is based in a customized content type ?

Any help with this?
Thanks