Installing the plugin locally using MAMP I get the following error message:
There was a problem with your feed! The error is WP HTTP Error: SSL certificate problem, verify that the CA cert is OK. Details: error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
This thread seems to indicate that the error is related to the MAMP server configuration:
Any clue? Thanks!
Edit: issue solved when updating WP.