When you run a LCD at msp430fr6888 make choose the clock source ACLK. Off VLO: CSCTL4 = VLOOFF; ACLK is running on LFXTCLK. But when using EnergyTrace Technology, see what works and VLO, and ACLK. When LCD is disabled, VLO is not working and can't figure out why begins to work when you run LCD.