If the folder has multiple folders, like if you see 2 or more and there is no oto for that make an oto with nothing in the oto file. Then refresh the voicebank and try again, That always works for me.
Edit, this is what it supposed to look like if it has multiple folders, there is a blank oto file outside the folders then utau would read the bank
The oto needs to be blank or else there would be samples that don't exist, hopes this helps ovo
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