When did you scrap your project and start over, and why?

I'm working on a second project at my company.

But as the project got longer and initially unplanned features started to pile up, the software has become a total mess and a pile of conversion layers for all sorts of I/O.

I'm starting to believe that it'd be better to learn from our mistakes and start over with a better plan, if it means we'll be able to achieve performance and stability improvements.

So, what was it like scrapping your project and starting over?