This guide serves as a reference to the issue that so rarely pops up in Rock Band where you are no longer able to start any game with DLC songs or cannot find your songs in the song list.

If you...

• Recently received a new xbox from microsoft
• Had this error popup randomly all of the sudden
• Purchased songs on someone elses xbox with your Hard Drive
• Don't know why your Rock Band keeps saying "The song data you were accessing has become unavailable, and the game cannot proceed without it. Your game session has restarted."
  

we have the solution here.

Part 1

We are first going to try the most simple solution and that is guessing that your DRM cache has become corrupted which can happen in power outages. Even if you don't think this is the problem, you should perform this step anyway to precede the next step's actions.

1. Go to your Xbox Dashboard
2. Slide to the System Pane
3. Go to Memory
4. Go to Games and then Rock Band
   
5. Delete "Downloaded Song Data" Only. NOT your songs or dave data.
   
6. If you have not received a new Xbox from Microsoft and you did not purchase your songs on another Xbox, restart Rock Band and see if this solved your problem.

Now if you fall in any of the following circumstances you will have to proceed through Part Two.

• The previous solution did not fix my problem.
• I received a new Xbox from Microsoft or had to buy a new one.
• I bought songs with my account on someone else's Xbox and now only I can use these songs on my Xbox.
  

Part Two

In these cases, you need to transfer the licenses of your content to your current Xbox. This can only be done ONCE PER YEAR as of 9/11/2008.

1. Visit Xbox.com | System Use - Transferring Content License to a New Console
2. Follow the instructions, you will need your Hotmail/Microsoft account information.
3. After you have completed the transfer, go to your Marketplace Pane.
4. Click Account Management.
5. Go to Download History
6. PAINSTAKINGLY select each song, then click "Download Again" to update your DRM license for the songs/packs. It's the only way, trust me I tried working around it because I have so many songs.
   

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