Lightroom 5 is no longer updated, and will never be able to read files from this camera (LR 6.6 is required), unless you use the latest version of the free Adobe DNG converter to convert the raw files to DNG files, which can be read by LR5.
Your other options are to upgrade to LR6, or subscribe to the Creative Cloud Photography Plan, which includes Lightroom and Photoshop for $10 a month.
Adobe only updates the current versions of Lightroom. Specifically, that would mean Lightroom 6 and Lightroom CC 2015. Support for any previous version is terminated.