Yes!! Gold certificates are paper, which means they are worth nothing. For every single ounce of gold or silver, the banks can sell hundreds of certificates laying claim to that ounce.
When hundreds of people line up to claim that one ounce of gold, the first person will be lucky to get it. The other people will be told "Sorry," and given a valueless piece of paper.
Do not waste any money on gold certificates or ETFs. Buy only PHYSICAL gold or silver.