To fix this, let's access your QuickBooks Online (QBO) account in a private browser. There are times that the browser is full of frequently-accessed page resources, thus causing a problem when running websites, like QBO.
Here are the shortcut keys you can use:
Google Chrome: click Ctrl+ Shift + N
Mozilla Firefox and Microsoft Edge: press Ctrl+ Shift + P
Safari: hit Command+ Shift + N
Once signed in, open the Trial Balance Report again:
Go to the Reports menu.
Scroll down to the Accounting reports section and select Trial Balance.
Click the report to open.
If you can successfully open the report, go back to your regular browser and clear the cache. It helps to boosts the loading time of web pages and improves the performance of your system. We also advise periodically clear them to prevent web problems. If not, you can use other supported browsers.
Also to guide you in filtering data and personalising your report in QuickBooks, head to customise reports page at this link for detailed instructions. This also includes steps on how to export, send, and print reports.
Feel free to get back here if you have other concerns about accessing the Trial Balance report in your QBO account. I'd appreciate any response and I'm always here if you need more help. Take care always.