Invalid stack ID after saving yml config

Created a new project in web cli. Tried to copy yml.config from older project to the new one. Can’t save the YML, I am getting an error Error saving app config: Validation failed: App stack Invalid stack ID:
I have no idea what is wrong? Checked the stack tab, have the ssame version in both projects. What error ? Is tehre a bitrise validation editor where I can check what is wrong with my config? I can easily edit and save the YML in the older project.

Formerly a stack id wasn’t saved to yaml. Now it is.
Try inserting an entry with desired stack id.
Look here: Setting the stack for your builds - Bitrise Docs