Here is the link to the song that isn’t complete.. The sing stood before the lyrics of the song are complete.. how many characters are too many? Are does that matter?
We are very sorry for the inconvenience caused to you. We are already making improvements now.
Just a quick note — Tunee currently supports up to 3,000 characters for lyrics and 300 characters for prompts. 
If your input exceeds that limit, you may need to shorten it a bit before generating. Hope this helps!