Unable to launch Delphi 10.3.1 Community version as a normal user

I just want to use Delphi 10.3.1 Community Edition. When I want to start it, the License Manager says : It does not find a valid license for C++ Builder Community Edition.and the License Manager pops up again and again. When I ask a serial number for C++ Builder, the License Manager says : there cant be two community edition product on the same machine. If I launch Delphi with admin rights it works fine. But in this case the source file dropping feature does not work. There is no option to create a C++ project if I run RX. The OS is Windows 10 x64. Any idea?