Let's perform some troubleshooting steps so you can process payroll successfully, parul-tailor-re.
To check if it's a data issue, let's try logging in to your QuickBooks Online (QBO) account via a private or a different browser. There are times that browser stores frequently-accessed data, thus causing websites, like QBO, to act weirdly.
To use a private browser, here's how:
Google Chrome: Ctrl + Shift + N
Internet Explorer: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + N
Safari: Command + Option + N
Once logged in, go back and try to process payroll again to double-check. For more guidance, you can check out this article: Process or run payroll