Follow these instructions to get a new activation code:
https://wiki.meteohub.de/wiki/index.php/Transfer
Make sure you copy down both the Old and New Activation Codes and System ID’s carefully as without them you will not be able to reactivate your Meteohub RPi and will have to email Boris to get a new one.
The system ID and Activation Code are tied to the individual SD card so a new one must be generated whenever you have to change SD cards.
Also, If you’ve replaced your SD card with a standard SD card, be aware that standard cards have a limited number of read and write cycles before they get corrupted ( which is why you have had to replace it ). To extend the life of your SD card, get an SD card that has SLC memory. They are much more expensive but will last much longer and prevent the situation you are in now from happening again for a much longer time period.
There is an 8GB SLC SD card on eBay for $39 US. It’s item # 144111473765.