For LPCXpresso IDE v8.1 and later: this FAQ applies to all supported Debug Probes.
For earlier versions of LPCXpresso IDE: this does not apply if you are using the original LPC-Link or Red Probe+ debug probes.
If you are building and debugging images for LPC18xx or LPC43xx MCUs which will be download to and run from internal RAM, rather than from internal or external flash, then the default launch configuration created by the LPCXpresso IDE will need modifying before you can successfully start a debug session.
To do this edit the launch configuration for your project and replace the "Reset Script" specified in the launch configuration script settings with "LPC18LPC43RamReset.scp".
For details of how edit launch configurations, please see the FAQ "Launch Configuration Menu".