"It was a disappointing way to start but systems were back up again within two hours and we quietly confident everything will run smoothly from now on," Allen said.
Allen said people who were online before noon did get to see the opening addresses which included one from the Prince of Wales, who attended the Fieldays 50 years ago.
"There has been little negative response from exhibitors or those trying to visit the site," he said.
During the opening ceremony Allen said it was 90 days ago the society had to pivot to an online event.
"If the farmers can't come to the feildays, we will bring it to them."
Earlier NZNFS chief executive Peter Nation said going online allowed them to reach a global audience, and claimed it was "a world first for any agricultural event".
The platform will host exhibitors' sites, a series of webinars, live video and sales.
Fieldays Online will remain open until 26 July.
- RNZ