[souffle]

Is the lid sitting correctly in the hinges at the opposite side? If it isn't the sliding bars won;t clear the lid to open it. It can be fiddly but you have to unhinge it fully and resit the bars and click in to place. I'd put the whole cage in the bath in xase the hammy jumps out in fright then transfer the ham to a carry box while you try and fix it. I have a couple of similar fop lids and they open ok