TM4C1294NCPDT: Can't receive data under release status

The configuration labels "Debug" and "Release" are simply example configurations. A configuration is the set of options used by CCS to build your application. When you change an option, such as when you right click on a project and select "Show Build Settings" and then make changes. The changes apply to one of the configurations. Most people start with the "Debug" configuration. Now if you switch to using the "Release" configuration, the changes you made to the "Debug" configuration have not been made to the "Release" configuration. Even if you have not made any changes to the "Debug" configuration of your project, the settings may be different between "Debug" and "Release" depending on what example project you started with. You can create other configurations as well. For example if you have a product that comes with multiple options, you may be able to build the different options using conditional compilations with different defines in each configuration.

Now, back to your question. Why does your application not work when using the "Release" configuration. I suspect it has to do with some setting that is different between your "Debug" and your "Release" configurations. You can step through the build settings comparing "Debug" with "Release". It might be the optimization level, or your include or library paths that are making a difference. You can switch between configurations by using the drop down list I highlighted in the image below.