I've found a similar question in the community but it didn't quite help me or I didn't understand it. I am in ArcPro for Desktop and I am trying to add a Domain. But when I click on my feature layer < Data < Domains I get "The Domains for this workspace are read-only". I saw a solution for ArcGIS Online, but how do I get this to work for ArcPro Desktop? Do I need to convert my layer to something? Or am I missing something?
What are you trying to a domain to? Feature database? Enterprise Database? If so, what type and version? How exactly are adding the domain? What is the source of the layer you're trying to add the domain to? AGOL? Portal for ArcGIS?