For that you will need to download the full Bitcoin blockchain.
I think it could be that your google chrome browser is not up to date. That is my one suspicion.
At this time omniwallet.org is pretty much the only way. I know of another way to do this, by providing a lite client; however, it is not implemented yet and I am waiting for our acquisition of talents in full stack developer so that they can gather the experience working on that with me. I know it doesnt solve your problem right now, just a heads up though for the future.
Summary: try to updating google chrome browser if that doesn't work try another computer. Omniwallet is working A OK for me.