Import yaml file for configuration is failed without clear explanation in both cms console and terminal

Tested on HAP.

Try to import hcm-config/hst/configurations/hap/workspace/containers.yaml file from bootstrap configuration folder under /hst:hst/hst:configurations/hap/hst:workspace.

Problem: Import failed without clear explanation in both UI  and terminal.

Expected: could be discussed. 

1. If import is not allowed - clear explanation.
2. If allowed - no errors.  

Note: In my case I needed to restore configuration to initial state using yaml file from bootstrap. Simple import of yaml didn't work as described in this bug. At the same time after discussion with PCentgraf and tjeger mechanism of restoring configuration is needed and not only for testing purposes. Moreover I tried to delete node which I wanted to restore (in my case containers node) and after that I still couldn't bootstrap that node from yaml configuration. At this point I would say that system doesn't have protection in case of accidental changing configuration to restore it back except shutting down and restart with clear repository. But I could imagine necessity to restore some particular node in configuration and not entire repository.