“Podcast cannot be played on this iPhone” where Podcast is replaced with your actual Podcast you attempted to download.
I actually had this same problem much before my iOS upgrade, and I discovered that this occurs sometimes, but not all the time. In my experience, it occurs in the following scenarios:
- When downloading over 3G
- When an ISP runs a transparent proxy server for its web traffic
- When a Unified Threat Management appliance or software Anti-virus protection scans http (web) traffic
The latter one applied to the most common places I frequent, and naturally we use Unified Threat Management everywhere possible. If you run UTMs such as ClearOS, Untangle or Astaro, disable Anti-virus scanning by URL, extension, or whatever exception you’re comfortable with. It’s worth noting not to be too liberal with the exceptions as you do want the protection of Anti-virus scanning for drive-by website downloads to be active for all other types of downloads.
In our own case, we decided to exempt cachefly.net domain from being virus-scanned since TWiT.tv’s podcasts are hosted there and they were the most common ones to be accessed from iOS devices.
If you’re wondering about your ISP running a Proxy to save on bandwidth, we have prepared a web-page to check:
http://www.iamanerd.com/whoami.asp (opens in a new window/tab)
Note that this page will NOT detect if your internal network runs a proxy, only if your ISP does. Here’s how you can tell:
Scenario 1: Your http IP and your https IP are the same: Your ISP does not run a transparent proxy server
Scenario 2: Your http IP and your https IP are not the same: Your ISP runs a transparent proxy server.
If the latter scenario proves to be yours, you may not be able to do much as bandwidth costs in many countries is differentiated between local and international, and the way ISPs can contain costs is by providing a cache/proxy service to their customers. However, if you have the option to request a proxy bypass, that may solve your podcast downloads as well as other common issues with Transparent Proxy servers.
If this has helped you or if you have any additional insight or help on this issue we welcome your comments!