I am currently working on a project using Corda 5 and while using CSDE-cordapp-template-kotlin release/corda-5-0, I encountered an error where the corda-runtime-os release 5.0.0.0 corda-combined-worker that it is trying to pull cannot be found on github. I looked at the Github releases and it is not available. It seems that the corda-runtime-os 5.0.0.0 release has been removed only recently since this was working previously.