With a themes-folder under config-folder
And themes-files in themes-folder
And no themes.yaml in config-folder
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The “new approach” B seems somewhat unstable.
Ok if you want to continue working to get way B working. Just let me know.
I would also like to understand what’s going on.
I know that doesn’t help, but I can’t understand why it’s not working for you and the error message implies that the formatting is wrong, but we know it’s correct because it’s @finity 's working config