Unable to perform Import KNIME Extensions

I have installed KNIME and trying to Install/Import KNIME Extensions , I am getting below error “some sites could not be found. see the error log for more detail. unable to read repository at https://update.knime.com/community-"“ . I tried all the possibilities shared in the Forum, no luck.

1. Help→ Install Soft→ Manage – DIsable Partner Sites, also tried Reload.

Please help with the right solution as I need it urgently.