Random "File cannot be read" when reading from NAS

This only started when I upgraded to 1.5.2. It can happen at any point in time during the stream from the NAS. To make things even more random, here's what I noticed so far:

• This doesn't happen with files that I copied to the NAS from my old disks, only from files I added to the NAS through torrenting.
• If I move the preview cursor on the TV to one of those older files and allow Serviio to start playing the preview, and then move it back to the movie I was watching, I can get it to play.
• However this isn't 100% reliable. Sometimes it just refuses to play at all.
• Sometimes restarting the server on the PC helps, sometimes it makes no difference at all.

So how do we troubleshoot this? I'm pretty certain that this issue was introduced with version 1.5.2.

I've reached a point where Serviio no longer streams any file whatsoever on the TV, even after I rolled back to 1.5.1. I fear that there's a problem with the way the Synology DS414 NAS is doing its RAID file management not being fully compatible with Serviio, but no one on the Synology forum is giving me any help to confirm that the problem is with the NAS.
I installed Plex, but the program starts many transcoding processes (like 8 to 10), driving my 6 core CPU to its knees, still giving me lots of hiccups and not allowing fast forward or rewinding. The fact that Plex requires movies and series to be in separate folder is pathetic, and the fact that it gets the names wrong, are a reminder of how much smarter Serviio is.

Is there anything I can do to get Serviio working again? Please?