This may be a browser-related issue, to fix this, let's run your QuickBooks Online (QBO) account using a private browser. Private mode prevents storing cache and cookies that might cause problems when running websites.
Here are the shortcut keys you can use:
Google Chrome: press Ctrl + Shift + N
Mozilla Firefox and Microsoft Edge: press Ctrl + Shift + P
Safari: press Command + Shift + N
Once signed in, attempt to print your W2 again. If this works, go back to your regular browser and clear the cache. This will remove the stored cache or cookies to refresh your browser. If the same thing happens, use another supported browser. It could be that the one you're currently using has a temporary issue with QuickBooks.
Also, for your future reference, I've added this helpful guide to help you learn more about answers to the most common W-2 questions. See this article: Get answers to your W-2 questions.
Feel free to get back here if you have further concerns about printing your W2 forms in QuickBooks. I'm always here to help. Have a great day.
Thanks for getting in touch with us again, @534199842,
Since you already did some basic troubleshooting to resolve the Forms section not loading in QuickBooks, I recommend getting in touch with our Payroll Team. This way we can report this to our engineers for a fix.
To reach us on time, our Live Help are available from 6:00 AM to 6:00 PM on weekdays and 6:00 AM til 3:00 PM on Saturdays. Follow these steps in your account to get a representative to assist you:
Go to the Help menu then select Contact us.
Enter the keyword Payroll Account Management and Billing in the What can we help you with? box.
On the next screen, scroll down to the Choose a way to connect with us section.
Choose Start messaging to initiate a discussion with a live agent or Get a call for callbacks.
When using the messaging option, make sure to enable pop-up windows. The chat box will appear at the bottom right section of your monitor, and an agent will be with you after filling in the information needed. See this:
When you're connected, provide all the information about your concern with our representative or request a viewing session.
For other concerns with QuickBooks, please let me know in the comment below. I'll be right here to help you.