Problems when trying to download Salient

Hello, (Sorry for my English)
I am totally a beginner in Wordpress and Flywheel. I have created a Wordpress count. I have bought Salient on Theme Forrest and I tried to download it on my Wordpress admin page. It failed several times. I always get this message ’

Local Router Error

Our apologies for the inconvenience. The Local router is not able to connect to the site you requested.

We suggest you try the following:

    Restart Site - Go to the Local by Flywheel app and restart the site you are attempting to access.
    Contact us - If the issue persists please contact us.

Can somebody explain me why I cannot install Salient and get this error message ?
Thanks for your help.