I have a solution that contains custom Umbraco Forms workflows and field types to work with a third party payment processor. I've been trying to add a new workflow to it but when I copy the dll (everything compiles fine) over to the server the workflow will not appear for selection in the menu. Interestingly I can make changes to existing items in the code base (i.e. guid changes cause errors, workflow icon changes), but newly created items do not not appear.

I also tried to add a simple field type and that is also not appearing for selection. Again, the same behavior, I can modify existing field types, but new ones won't appear.