Had huge problems bacause of Mevio. For my 2c worth it is causing so many user problems freezing iTunes that this MUST be SORTED BY ITUNES!!!!!!
Mevio was a host site that has suddenly ceased operation. Anything using this host will be "dead" until new hosts are found. Unfortunately itunes will have the old link and because Mevio has been erased, we are now left high and dry and this is what is causing itunes to freeeze. As I said this must be sorted by itunes as Mevio had over 36 million users. How many of them are tearing their hair out and wasting countelss hours, for many fruitlessley.
However here is my eventual solution in a Windows 8 environment (there would be a similar solution in Mac environ, but I dont know that system). Sorry it is long winded, but it worked for me.
1. In iTunes Podcasts click on the little cog symbol of any podcast. At the bottom click the Default Tab and turn of Download Episodes. This will cease all podcst down load activity when you hit the refresh button. Now you have time to act before the "freeze" happens.
2. in Itune Podcasts on the left menu bar, which should display your subscribed podcast list. Right click on each podcast title. A menu should appear and in bottom thirn you will see "copy podcast URL". Click on this to copy the URL or feed address of that podcast.
3. Paste this into any text editor, or word processor (MSWORD or event NOTEPAD). You can now see the feed address. If it has anything with "mevio" that will be your culprit/s. Do this for all your feeds/podcasts before next step.
4. Try unsubscribing from offending podcast/s, but like me it will probably FREEZE because iTunes will want to contact Mevio to unsubsubscribe. Instead I Right clicked on the podcast tiele and selected DELETE from the menu and placed that podcast in the recycle bin for later trashing.
5. Once all problem podcasts have been deleted, go back to the little cog symbol for any podcast, click on default and turn on "Download Episodes.
Now I can refresh podcasts without the dreaded freeze.
Hope you can follow this.... Im a swimming teacher, not a techie.