I would assume this is the point of contention:
The Jazz want Jae Crowder, but are only willing to give up a lottery protected 1st.
The Celtics think they can get that from a different team, and possibly something on top of that (like a young player on a rookie deal), so they are probably trying to get Utah to give up the pick with less protections.
The Celtics are now weighing their options and will almost assuredly find someone to deal with them.
Why wouldnt a team like Denver give up Juan Hernongomez and Mike Miller, along with a protected draft pick, to get Jae Crowder? Mike Miller is a non-guaranteed contract, so I think they can do that deal to free up space.
Or they could give up Trey Lyles or Tyler Lydon along with Mike Miller. They have so many young guys on rookie contracts they can easily deal one, attach it to Mike Miller, along with a protected pick and instantly do a better deal than anything the Jazz would willingly do.