We have an old server running unifi 2.3.9 controller.
Installed 4.6.6. on the new server, did a backup from the old, tried restore and it said you can't import 2.3.9 into 4.6.6. So I thought I'd get a mid version - 3.x.x on the old machine and upgrade in steps?
But can't see where to get old versions of unifi controller. any advice?