It is possible the installation is detecting a corrupted or outdated license file. Either because of previous version serial numbers you have registered that has no subscription or previous trial licenses you have used that is being detected by the registration.

Please do the steps to clear licenses that could cause issues with the install.

1. Remove any *.slip or reg*.txt files located in the following directory:
C:\Users\<your user name>

2. Delete or rename directory the directory below (note that this will also delete existing serial numbers you have in the License Manager which you can simply re-register back later):

C:\ProgramData\Embarcadero

3. Clear out and delete all files and folders in your temp folder:

C:\Users\<your user name>\AppData\Local\Temp

4. Relaunch the product and re-register. Optionally, you can re-install by following Step 5.

5. If problems persists, please delete C:\ProgramData\Embarcadero followed by a clean removal, using the steps below before reinstalling:
https://blogs.embarcadero.com/manual-uninstall-of-rad-studio-delphi-cbuilder-10-4-sydney/