I would first of all suggest that you study Chapter 14, "Memory Configuration and Linker Scripts", of the MCUXpresso IDE v10.1 User Guide, which explains how linker scripts are handled in MCUXpresso IDE.
There have been a lot of changes made since the last Red Suite release back in 2013. But exactly what might be causing you issues really depends upon how old a version of Red Suite you were previously using.
I would suggest that it would probably be worth looking at the LPCXpresso IDE v8.2.2 Installation Guide, which contains some migration hints and tips on moving from older IDE versions. You can download this from the "Documentation" tab of:
https://www.nxp.com/lpcxpresso
And then you could also look at the the MCUXpresso IDE v10.1 Installation Guide too, which some information on migrating from LPCXpresso IDE too (in your install directory, else downloadable from MCUXpresso IDE|NXP ).
Regards,
MCUXpresso IDE Support