Hello @ZhangJennie
Thank you for the suggestions. We will try the ISP mode.
We solved the problem. There were two main issues.
1. There were two XML .project files in our project. This led to a very long project because every time we did an export the entire project was copied to the previous debug folder. We cleaned the project outside of the IDE.
2. During our tries to make a release launch the LPC11U68 chip locked up and no longer oscillates. A second PCB works OK.
We are trying to get the bad chip to come alive by using FlashMagic, but will probably replace the chip.
3. The Release launch needs the chip and the board projects to be also recompiled in release mode.
4. The LS link server file is added to the project during a successful launch.
jDrum