That moment when you realize you're screwed

Hey there.
I am the owner of a forum hosting company. We host more than 4500 forums, and this is not the spam thread you would expect with a beginning like that. It uses the EchoPHP software which was sold by this user on DigitalPoint.

It was a closed-source forum hosting software which had quite a few clients, currently active forum hosting providers. The trouble is, their website echophp.com disappeared a few days ago.
Having in mind the recent events with it, it isn't likely to reappear.

Basically, its disappearance lead to us being unable to provide support to our users and cut any access to our administration functions. This is because of a license check which we cannot override because its source code is encrypted. They were using the PHP Audit system for license checking, and it would probably be illegal for me to attempt to crack the encryption and override the check. Also, PHP knowledge is not enough to do it.
And the biggest trouble is I can't even shut down the paid options because the source code is encrypted. So my users can use everything, they don't have a clue about what happened, they can still pay me and use the paid features. But once or twice every few months something goes wrong and I am unable to provide support.
Additionally, I can't notify all the administrators because there are 4500+ forums and there's no way for me to see their administrators' emails.

I am looking for a way to resolve my issue because a large business project that I own depends on it. For now, I am just looking for a way to contact the owners. I wrote to everyone I could in order to get in touch with these guys but I can't yet.

I don't have the knowledge or the resources to find out how to deal with the issue legally when I am on the other side of the world. Just wanted to share my story and seek your insight or advice.