HA Yellow CM4 yellow light flashes

While upgrading HA Yellow to CM5, my system was wiped and would not accept a recent backup. I have managed to rebuild the system to about 90% on the original CM4 but there is a concern. With the original build, the green light was the only light active. Now, the yellow light is continually flashing along with green. The system operates but I am sure the yellow light flashing is indicating something is amiss.