Correct deactivation on old computer but problems downloading on new computer

Hello! I have just deactivated my SDL Trados license on an old computer, but when every time I click on the "Download" button on my new computer, a new window opens for a brief second and then automatically closes again. It seems as though something is blocking the download process, but I have no idea what that could be. 

Can anyone help me with this?

Thanks in advance for any suggestions you may have :-)