You experienced renoise.com being down yesterday. This was due to a system / software upgrade. Weird as it seems ShareIt is also doing at the same time system upgrade so at the moment you cannot register. (you can leave e-mail address and receive notification when ShareIt is back online). This shouldn’t take more than 2-3 days (probably less).
We are sorry if this causes some inconvenience. If you have questions about any of this please contact us.