Fatal error and what it means

[SWATCorac 3]

All 16 of my servers were up and running fine last night at about 11 pm. I turned them off for the night and when I restarted today I am getting this error. I know it has to do with the Redis db(i think) but not sure what. I verified that the redis is on. anyone able to explain the error to me? https://gyazo.com/11bc9293083d65b22ac477cf8d0b25ac

 

[SWATCorac 3]

Well as it turns out yes it WAS a redis issue. the password I set got reset to the default pass when something updated a few hours ago.