I built a site for a client on EE1, and advised them to buy a license to install on their server. Unfortunately they bought an EE2 license.
Upgrading the project to EE2 is not an option. Too many plugins, extensions, and modules would have to be rewritten.
How do we deal with this? Can they simply download EE1? Or do they need to get a refund of EE2 first, and then buy EE1?