This isn't Indigo-related per se, and definitely not in my case, but it could potentially be for others, so I thought I'd share.
I keep my music and my iTunes library on a Drobo NAS and have been having huge issues with iTunes. It flat would not load. Froze every time. Hasn't been stable since upgrading to Sierra. I downgraded iTunes, recreated the library, etc.--pretty much everything short of downgrading the OS--and nothing seemed to work. Then I stumbled on what *seems* to be a "solution".
I use the Drobo Dashboard and it mounts the Drobo on my Macs at boot with a friendly name (using afp://). I came across a post (somewhere) that suggested that mounting the Drobo using Samba (smb://) would work better. CMD-K (or Go->Connect to Server) and mount the Drobo manually using Samba (smb://10.0.1.123). Started iTunes, pointed it at the new mount point and iTunes started virtually instantly.
I suspect this is more about the protocol than the brand of device so, more generally: if you're having gremlins with a NAS device (or applications trying to access a NAS device), try mounting it with Samba. You might get lucky.