Lightroom 5 is a standalone version of Lightroom. Lightroom CC 2015 is a Creative Cloud version of Lightroom that is subscription-based, and is not a free update to Lightroom 5. If you want to stay with Lightroom 5 and use the raw files from your new camera then you will have to convert them to DNG using the free DNG converter. Another alternative would be to purchase Lightroom 6. It is the last standalone version of Lightroom, and has received the last update it will ever receive. But it will have support for your camera. Another alternative would be to subscribe to the Creative Cloud and have access to the current version of Lightroom. But you cannot get an update to Lightroom 5 that will support the native raw files from your camera.
LR 6 is not an Update to LR 5. LR 6 is newer release and is only available as an Upgrade from any previous version of LR and costs money to use.
You will need to get the Free Adobe DNG converter program and convert your new camera RAW files to DNG file that you can then import into your older version of LR.
Jim, thank you for your response. Yes, apparently that is the answer, not the correct answer, but the only answer that Adobe will support. Thank you for pointing me to DNG, which I installed, and now I am able to process my files. I do find it interesting that Adobe's customer support system forces an individual into a "pay to play" system for an update! Just another example of corporate greed.
Adobe is constantly improving their product. Thousands of employees. There needs to be revenue to pay those employees. You call that greed? Okay, so be it. The subscription plan works for Adobe. It works for many users. If it doesn't work for you, then that's okay too. It seems that it doesn't work for quite a few people. But I don't think it's going to hurt Adobe.
Let me state this again. LR 6/2015 is not an UpDate. It is a Newer version from LR 5. Just like LR 5 was a newer version from LR 4, 3, 2 or 1.
And all are UpGrades from older versions.
What you expected to buy LR once and then get all newer versions for free. That's like thinking if you bought Windows 3.11 back in 1994 you got all versions of Windows, 95, 98, XP, Vista, 7, 8.1 and 10, as they came out from Microsoft for Free.
Or if you bought a new car in 1990 you could take it back to the dealer in 2005 and get a brand new car for nothing.
That would be nice, but isn't going to happen.
And just to add to that, I first purchased Lightroom 2. Then I purchased an upgrade to Lightroom 3, another purchase of an upgrade to Lightroom 4, another purchase of upgrade to Lightroom 5, etc., etc. There ain't no free lunch.