Failed-to-create-custom-indicators-error-on-multiple-instances-of-WL8

I recently created a couple custom indicators, and they are working fine. However, any time I try to open more than one WL8 client (which is multiple times every day), I get an error box stating: "Failed to create custom indicators". Despite the error, everything seems to work okay, but it's a nuisance to see this every time I launch a new WL8 window.