eSellerate is the third party library that kJams uses to manage:
- built-in shopping cart (in-app purchase)
- licensing & activation
- serial numbers
kJams can run without all this, it's called "Tryout" mode. But in order to purchase kJams, or activate an existing serial number, kJams NEEDS to use the eSellerate library.
What's the Problem on Mac?
eSellerate recently made an update to their servers which lock out old versions of the macOS, specifically, any macOS older than 10.9. That means 10.4 through 10.8 can no longer be supported.
The technical issue is that the TLS / SSL libraries built into macOS had a severe security flaw in it, and apple chose to ONLY fix that flaw with security updates for 10.9 and up. Apple refuses to support the older OSs with their security update. And eSellerate refuses to work on any OS that does not have that security update.
If you're currently running on an older system, and you're NOT in tryout mode, you're at risk for reverting to tryout and not being able to ever get out of tryout. DO NOT upgrade your OS unless you can make it all the way to 10.9. ie: if you're on 10.7 or earlier, and the max OS your computer can take is 10.8, DO NOT UPGRADE!
Symptoms include: a totally blank window when you attempt purchase, a purchase failure, or "there was an error with that serial number".
If you think you can just "go back to a previous kJams or macOS version that was working" then you're not understanding. eSellerate controls the activation servers worldwide, and they have upgraded their SERVERS and will never ever downgrade them. It won't matter what OS or version of kJams you try, they ALL must talk to the eSellerate SERVERS, which will NEVER WORK with an older macOS no matter what.
Unfortunately there's nothing that I can do about this situation. If you're in Tryout mode, the ONLY way out is to update to 10.9 or later.