I upgraded a short time ago and I have tried several times to register v24 using the key emailed to me. Registration fails with "The activation key ... does not correspond to version 24.0"
Luckily, I still have v21 installed and working, but apparently I was sent an invalid key for v24.
Luckily, I still have v21 installed and working, but apparently I was sent an invalid key for v24.