MPRestError 101

Hello pymatgen users,

I have a ploblem to get data from MP by using API. My code does not work due to MPRestError no101(connection error). I tried some times with different API keys. But the problem is not solved yet. Error message is shown below. Could you tell me how to solve this problem.

MPRestError: HTTPSConnectionPool(host=‘’, port=443): Max retries exceeded with url: /rest/v2/materials/mp-3748/vasp/bandstructure (Caused by NewConnectionError(’<urllib3.connection.VerifiedHTTPSConnection object at 0x7f15908da8d0>: Failed to establish a new connection: [Errno 101] Network is unreachable’,))