Student licence problem

Hi,

I have problem with license in Substance 3d Painter.

First,I downloaded a trial version. This version worked fine, so I decided to apply for the student licence.

When the student licence is confirmed, I downloaded a licence key and saved the file according to instructions.

https://substance3d.adobe.com/documentation/spdoc/activation-and-licenses-142213404.html

Now, I receive this message and can't start Substance Painter

We can't verify your subscription status.

Your Adobe substance 3d Painter trial has ended.

We can't reach the Adobe servers. ........

Can you tell me what is the problem and how can I solve this problem.

I need Substance Painter for my study almost everyday, so this is a very important for me.

Regards