I've been debugging a complication of mine for several weeks now, and I am completely unable to figure out what runtime behavior (crash? hang? out of budget?) causes it to go completely blank.
I've left the exact same complication running overnight in the simulator as on my real watch, and my real watch (Series 2) will go blank yet the simulator catches no crashes or other failures that I can tell.
Does anyone know what going blank means for a complication on watchOS?
Sometimes it’s just watchOS, I think. When was the last time you power cycled the Watch? Also, have you looked at the Watch log files for your app? In devices from Xcode, you can view all the logs. See if there are any crash logs for your app on the Watch.