The download is ok.

https://my.aximmetry.com/User/MySoftware

Enter the DE or SE serial KEY

Hi,

You experience this, because you registered a long time ago, when the DE version was not yet available.

Now we've added the Community DE license for you, please use the DOWNLOAD button beside it.  Thank you for your interest and sorry for the inconvinience!

Is the Aximmetry Community DE not available anymore?
I want to learn first before buying a license.

Hi,

Community DE has been discontinued for quite some time.
You can find the currently available license options here: https://aximmetry.com/products 

The Studio Limited license is free, and you may use it for learning purposes without a time limit.

Note that Studio Limited does not include Unreal Engine support. However, if you only want to learn how to use Aximmetry, and you are already familiar with Unreal Engine or do not plan to use it, that should not be a problem. The native Aximmetry workflow and the Unreal-based workflow are quite similar within Aximmetry.
If Unreal scene editing is required, you could purchase the 1-month AX Scene Editor subscription upgrade for the Studio edition.

Warmest regards,