Why though. I get the same issue now, both with Plex Media Server (PMS) version 0.9.7.28 and 0.9.8.0 (currently plexpass only).
I want to require authentication on my local network and not get media server is unavailable every time a secondary user logs in. This also doesn't happen only on my local network however, when accessing externally using any secondary account the same issue occurs. I basically cannot run a single request without having to hit reload a few times to get it to work.
It's obvious it's a server issue, has nothing to do with file access or permissions. If you use a network logger you can see that the requests are simply timing out, the Plex Media Server is not responding quickly enough. It honestly appears that the Plex Media Server's web server simply cannot handle many concurrent requests.
Just trying to load a static image included in the Plex Media Server, http://your-plex-ser...web/img/sad.png will cause an "ERR_CONNECTION_TIMED_OUT" error. You force it to happen you simply have to click refresh repeatedly about 5-10 times. Considering how few requests it takes to cause this to happen, I can image that the majority of the time you are using Plex/Web there are more than 10 resource files being loaded per page, and as you navigate new images, metadata and directory listings are being loaded asynchronously.
This is probably the single worst thing about Plex, because it makes it so I cannot actually share my plex server with friends. They try to access the media and get so annoyed with it they give up. I was previously hosting on a Ubuntu Server for about 6 months and this because so annoying I reformatted my old gaming desktop and I have now have Plex Media Server running on an overly beefy Windows 8 server edition and migrated my 6TB of data that was previously spread out over 5 hard drives to brand new Western Digital RED Nasware drives. The same thing happens. It clearly has nothing to do with processing capability or file access, file reading speed (as the media server caches are on an OCZ Vector Series SSD) and it entirely to do with some internal software bug.
I'd really like this one fixed. I wish I could fix it myself because of how annoying it is, but Plex isn't open source :-( I support the developers though, have now bought plex apps for Android, Google TV, Windows 8 and have a PlexPass subscription; but alas, the core bugs are not being fixed.