Not a Valid Donor Address

I'm just wondering why Heidi is now showing the Donate button and "Not a valid donor address'?

My email hasn't changed. This a problem with the server?

Maybe your donation was more than 5 years ago? There was a grace period for such old donations, which did not fell under the current policy (1 year valid below 50 EUR). That grace period is over now :)

If you email me with your donor email address I can tell you more exact what happened.