F2810 Code Security Password Issue

Hi,

I am using F2810 and XDS510USB emulator.

I am new to this  Code Security function. 

Today, I used On-chip Flash Programmer, changed the Key 0 ~ Key 7 to FFF0 and successfully did the "Program Password". Then I flashed the .out file.

However after cycling power, I can not flash the F2812 anymore. 

When I clicked "Unlock" with correct password, the On-Chip Flash Programmer window showed me unlocked. But when I click "Execute Operation" to erase the sectors or flash the .out file, the On-Chip Flash Programmer window just went grey. The target board behaved just like been reset and run. 

Anyone can help?

Thanks.

Charmaine