Why Is Opera Mini Not Opening On My Samsung Galaxy Y When Connected To Wifi

Whenever I try to open Opera Mini with WiFi, it does not open and keeps on loading. Whereas if I recharge my SIM for the data usage (Internet) and open Opera Mini, it opens normally.

Also, the default web browser of the phone works in both cases, i.e. with WiFi and normal internet recharge.

Are there any specific reasons for it? Or is it like WiFi doesn’t support Opera for my phone?