I had a Coindice too, and asked someone to fix it. All went well, but the script got hacked anyway so ... I believe there is a backdoor that allows to empty wallets in it.
Anyway, please check the threads about johny1976 (the original dev of Coindice/coinjack/etc..) :
https://bitcointalk.org/index.php?topic=920645.0 (for exemple)
A lot of script owners got their wallets emptied, and with johny missing now it makes me think of some scam to take some BTC from people.
I advise you to be cautious with that script !