Buffering with Roku client

My plex server is a Ubuntu box with internal hard drives for media. Lately I’ve been getting a problem where plex buffers, usually just once, around a half hour into a movie. After it buffers this one time, it usually plays the rest of the way through no problem. I’ve attached the logs. It happened again at 08:17 am today (Sep 10). This log capture is from about one minute after it buffered so the event is close to the end.

I see two entries like this:
Sep 10, 2017 08:17:49.248 [0x7f0a673ff700] ERROR - Throttle: timed out trying to read chunk 1
Sep 10, 2017 08:17:49.564 [0x7f0a627ff700] ERROR - Throttle: timed out trying to read chunk 1

Do I maybe have a hard drive problem? I’ve not seen any other errors to make me think I could have a HD issue so I’m not really sure what to think.

Media details:
Media

Video Resolution 1080p
Duration 2:16:17
Bitrate 10641 kbps
Width 1920
Height 798
Aspect Ratio 2.35
Container MKV
Video Frame Rate 24p
Audio Profile dts
Video Profile high

Part
Duration 2:16:17
File The Matrix (1999).mkv
Size 10.13 GB
Audio Profile dts
Container MKV
Video Profile high

Codec H264
Bitrate 9135 kbps
Bit Depth 8
CABAC true
Chroma Subsampling 4:2:0
Duration 2:16:17
Frame Rate 23.976 fps
Frame Rate Mode cfr
Height 798
Level 4.1
Pixel Format yuv420p
Profile high
Ref Frames 5
Scan Type progressive
Width 1920
Codec DCA
Channels 5.1
Bitrate 1510 kbps
Language English
Audio Channel Layout 5.1(side)
Bit Depth 24
Bitrate Mode CBR
Duration 2:16:17
Profile dts
Sampling Rate 48000 Hz
Codec SRT
Language Nederlands
Format SRT

Server details:
8-core i7 4790 CPU @3.60GHz
8GB RAM
Ubuntu 16.04

Thanks in advance!

This doesn’t seem to be happening with any other clients, just my Roku. It happened again about a minute before I pulled the logs in the attachment here.

I sure could use some help figuring this one out. Thanks in advance!

Roku has a bug in their latest 7.7 firmware that causes what you describe. There is an updated 7.7 version that fixes the problem for most people that you can request. See this thread on the Roku forum:

It is a quite long thread but the relevant part is:
From: RokuShawnS - Roku Engineering

Send me an email (ssmith@roku.com) with the following information:

Name
Serial Number (Settings > System > About)
Roku Model# (same place as above)
Email address
I’ll get you on the new patch that fixes the plex issue.

Edit 2 Please include the word “Plex” somewhere in the body of the email so I can more easily filter

I have this same exact issue. I was about to send the email to get the newer build, but checked for updates before I sent it and build 7.7.0 build 4144 is available… so I think that is even newer than the build that would fix this issue. So hopefully that’ll resolve this.