When flashing the BIOS to 1.6.0, you get Warning!! CPU is Over Clocking. You are about to flash your bios, make sure overclocking is turned off.
The OK button stays disabled, leaving you the only option to cancel. (See figure 1)
Figure 1: Warning message about CPU Over Clocking
The warning interrupting the BIOS flash is caused when the Overclock setting is enabled. The OK button on the warning message stays disabled until overclocking is disabled.
Follow the instructions below to turn off the Overclock settings to be able to flash the BIOS to 1.6.0.