Some Fidelity Investments customers were in for a nightmare scenario on Wednesday: when they logged into their online portals, they saw they had no balance — or, in some cases, no account at all.

The Boston-based financial services company is fielding complaints on Twitter from users who say they can’t see their retirement accounts, or their other investment or checking accounts. The problem appears to have started in the morning, though the company was still responding to Twitter users as of 3 p.m. EST.

The company said some clients were experiencing intermittent technical issues and that they have now been resolved. There was also a service alert on the site. ”We are experiencing website difficulties,” it said. “Try logging back in, and if the problem persists, please try again later. We apologize for any inconvenience.”

Fidelity has 30 million individual investors, 29.6 million brokerage accounts and $7.8 trillion in total customer assets, as of Sept. 30, 2019, according to the company. It manages more than $1.5 trillion in retirement assets.

Last week Fidelity reported that its retirement accounts, on average, performed well in the fourth quarter. The plan sponsor said more employers are automatically enrolling their employees in retirement accounts, and automatically escalating their contributions yearly, too. Average 401(k), 403(b) and individual retirement account balances increased in the last quarter, as well.