Freezing video playback

So, a couple of days ago, someone in my household tried to turn on a movie while I wasn’t home…and they met with frustration when movie playback froze every 3-4 minutes. Error displayed was “We are having trouble playing this video. Please check your playback setup.” I’ve replicated the problem, but I’m not sure what’s causing it. Playback device is a PC running Windows 10, with a wired ethernet connection to a Buffalo gigabit router that the local Plex Server also has a wired connection to. Server is running Windows 10 Pro (x64), Plex Server is version 1.1.3.2700. See the screenshots below for more details, including the specific error the web client displays, an XML version of the file information, and general hardware specs of the server.

I’ve enabled debug logging on the server as instructed here - https://support.plex.tv/hc/en-us/articles/201643703-Reporting-issues-with-Plex-Media-Server - and have a download of the logs, which I’ve attached here. Date/time of error reproduction was this morning (Sept 18) around 8:30 am.

What’s going on with the freezing video playback?