Activate License Spinning
I just had my sdcard crash on my Pi. I rebuilt the Repetier-Server image on another card. Going to activate my license, i enter it, click activate and the little circle shows up showing its doing something and never goes away. If i refresh the page the register box actually goes away so it only shows the free/pro comparison.
for typical reasons why activation fails. With new image it is not the certificate, but maybe time was not correct when you tried. Needs a bit on new images to fetch and update it from network time server.