Bundle item tabs do not open nor can I add one

Hi,
I just bought these plugin as I thought this is perfect for what I need. But I can’t work with it. As soon as I switch to Bopo bundle I can’t oben the “Bundle item 1” and “Bundle item 2” tab nor can I add some new items. So I can’t configure anything at all.

I tried with Chrome and with Firefox. Doesn’t work anywhere.

Please help me out on this issue, thanks