I AM ALSO EXPERIENCING SAME ERROR PROBLEM. I ENTRED MY SALES RECEIPT WITH ONE DATE AND AS I AM TRYING TO SAVE IT GIVES ME THE INVALID FORMAT NAN ERROR. HOW DO I CORRECT IT
I appreciate you for joining this thread. Let me share some troubleshooting steps to get rid of the error message.
Most common issues in QuickBooks Online are usually a result of too much accumulated historical data. Whenever you visit a website, it saves some information from the web page in its cache and cookies. These files allow the websites you visit most often to load faster. Not to worry, clearing them will do the trick.
First, let's try accessing your account through an incognito window to rule out the possibility of a webpage issue. You can refer to these shortcut keys to open an incognito window in all supported browsers:
Chrome: Ctrl+Shift+N
Firefox: Ctrl+Shift+P
Safari: Command+Shift+N
If you're not getting the same error after saving the sales receipt, switch back to your regular browser. Then, clear its cache. This way, you can access QuickBooks with a clean slate. You can also use a different supported one.