I cannot install applications from APP Center

When I try to install the application from the application center, I get an error
# Error performing the action
The requested action cannot be carried out. Please consider the information listed below in order
to resolve the problem and try again.
For the installation of this application, a UCS license key with a key identification (Key ID) is
required. You receive such a license key within a couple of minutes via email after a free
activation.
ACTIVATE UCS NOW

I installed the system (ESXI image), after incorrect settings, I completely reinstalled the System.
Having received an error with synchronization and license, I came across a theme form: UCS joining an existing Windows Domain not working.
Following the recommendations for clearing DNS records, I reinstalled the system again, but the error reappeared.
After reading other topics with a similar error, I followed the steps from the article (Upgrade from 'Free for personal use' to 'Core Edition'), but the error also comes out .
Please help with the problem.

The license is installed normally
Activation of Univention Corporate Server
The license has been updated successfully.
You can now continue to use UMC, all applications in the Univention App Center are now available for installation on this system.