The boot loader of the Connect ME can indicate a range of problems via the Network Activity LED.
This particular blink pattern indicates that the EOS (Embedded Operating System) has failed its check.
The way to resolve this would be to reload the EOS into the ME's flash. If this ME has a JTAG interface the reloading can be accomplished via GDB using the naftpapp example. For units without a JTAG, please contact Digi Technical Support for assistance.