"HTTP Error Bad gateway" while setting up Prometheus data source

Hi ,

We are trying to add new Data source using prometheus for one of our Dashboard. Unfortunately we getting Bad gateway error after clicking Save& Test button and below error message via email notification

Error message

tsdb.HandleRequest() error Get http://XXXX:9090/api/v1/query_range?end=2019-07-30T05%3A43%3A09.9564199%2B02%3A00&query=%28wmi_logical_disk_free_bytes%7Bvolume%21%3D%22HarddiskVolume1%22%7D%2Fwmi_logical_disk_size_bytes%7Bvolume%21%3D%22HarddiskVolume1%22%7D%29+%2A+100&start=2019-07-30T05%3A38%3A09.9564199%2B02%3A00&step=15.000: dial tcp XX.XXX.XX.XXX:9090: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.