Suggest you convert CR2 to Adobe raw (DNG)or purchase LR6. You can get the latest DNG converter 9.1 for Windows or Mac from the following link. The DNG files will then work with your present software (keep your originals as backups and for use in the camera manufactures software)
To download click here - DNG Converter 9.1
You can convert a whole folder of raw images in one click. See this quick video tutorial:
You need Lightroom 5.7 or later. So you can purchase the current version (or use the 30-day free trial) of Lightroom at the upgrade price (79 US Dollars).
You could download the FREE Adobe DNG Converter version 8.7 or later and use that to convert your RAWs to DNG, and import those into Lightroom 3.
I have even downloaded the newest free trial version of lightroom to try for 30 days... still nothing.... PLEASE HELP!
If you have the free trial of Lightroom CC 2015 (is that what you have? please confirm the version), then it will read the RAWs from your camera. So what happens? What is the EXACT error message?
Thank you so very much!!!