Did you know that the CSL for C6455 is made to work with CCS 3.3? So if you have CCS 3.1 and earlier versions, you will need to update it in order to use it. This information is in the release notes of the CSL itself, which you can download at the link: 

 http://focus.ti.com/docs/toolsw/folders/print/sprc234.html   After you download it, you can find the CCS and compiler versions used to build and test this release of CSL at the following document, page 3:

 

…\6455\6455_default_package\default_package\Releasenotes_C6455_v3_00_10_02.pdf  

 

Please keep in mind you still can use CSL with higher CCS and compiler releases.