Cannot install plugins

Hi all.

I have just bought a license and installed Studio 2021.

I am trying to install MyMemory and MT Cloud Provider plugins, but after downloading them, I click on them and nothing happens.

I understand that the Plugin Installer is supposed to open but it does not. I also tried by manually open it in advance from the Program Files and then click again on the plugins downloaded but I had any effect.

Any suggestion please?

Thank you,

Paola