If the issue(s) happen with files over the network via the NAS and not with local files, that suggests to me the source of the issue(s) is likely network related.
Believe me, I am not a JRiver expert, but I do not think so.
Let me split the problem into two part:
1) First part: audio interruption playing JRiver as configured after a fresh install
After a fresh install, Memory Playback is DISABLED. OK. I am not a memory playback fanatic... I just wish to have things working.
I open any FLAC file on my NAS with one eye on the task manager and my hears wearing my AKG
Sound and network activity immediately start.
After let me say... 5-10 seconds, network activity stops but the sound still plays
after a while network activity restarts again and sound stops with noise but immediately restarts
Let me say that: if I copy a huge file from the NAS, the network activity is high and is costant until the file is copied
Playing the same file... no... it is loaded with "network spike"... up to 200-300-400 Mbps
I hear sound problems every time I have one of this "spike"
Switching the WiFi from "ac" to "n" will produce again spikes in the network activity, but these spikes are lower and longer (it is obvious... less bandwidht) and I have less
audio problems
2) the second problem comes trying to find a solution to the first one
In my mind: if the network activity produces audio problem... let use the Memory Playback!
In my mind it let JRiver to load the file into memory then (and not before or during) JRiver should play it
I do not know if my mind is right or not... but what I was supposing, does not happen.
Even with Memory Playback set to ON, the behaviour is the very same as before... the file is played back immediately, without waiting for the file to be fully loaded into memory and I have the same network spikes as before
I must admit that some time Memory Playback works: hitting play will produce the message "buffering" and works correctly.
P.S.: some time I noticed a pop-up saying "spinning up hard drive..." (hard disk on the NAS have spin down disabled)
More clear now?
If problem 1) could be originated from network infrastructure, WiFi, NAS... whatever...
then Memory Playback should be the solution, but it does not work as expected and I have to face problem 2)
For sure... problem 2) is because of JRiver and not the infrastructure