What is error: unexpected token < at JSON at position 0?

Hello there, @PEInc.

The JSON error is caused by your browser's data. There are times that the browser store frequently accessed data, thus causing QuickBooks Online (QBO) to get unusual errors like this. To sort it out, let's perform some troubleshooting steps to check data issues in your browser.

Before we proceed, may I know what you're trying to do when getting the error? Any additional information would be greatly appreciated.

In the meantime, let's try logging in to your QBO account using a private browser. Press this shortcut key on your keyboard to open a private browser:

• Press Ctrl + Shift + N on your keyboard for Google Chrome and Mozilla Firefox. 
• Press Command + Shift + N for Safari. 

If this works, it means that you need to clear the browser's cache so the system can start fresh. If you get the same result while using a private browser, I recommend switching to a different one.

As always, you can visit our QuickBooks Community help website if you need tips and related articles in the future. 

Please feel free to keep in touch with me here on your progress with this, I want to make sure you're taken care of.

This error is super annoying and I get it all the time instead of blaming the browser maybe Quickbooks programers should fix their code so that the program doesn't react this way. I get this code 3-4 times a day and I'm to the point where I am going to switch to a better program.

I would have also been disappointed by this error message, Norlog.

I know it hasn't been easy experiencing this all the time. Let me make it up to you by ensuring this error gets investigated.

I'd recommend contacting our QuickBooks Support Team. They're equipped with tools to determine the cause. It'll also allow them to submit a ticket to our engineering team to alert them about the issue if necessary.

Here's how:

1. Go to the Help (?) icon at the top.
2. On the Assistant tab, click Talk to a human.
3. Enter your concern in the Type something field, then click the send icon.
4. Click on I still need a human.
5. Select Get help from a human.
6. Choose Chat with us or Have us call you.

Please check our support hours to know their availability.

I've also added our View All Help article for future reference. You can browse topics that'll help you complete your QuickBooks tasks.

I appreciate your understanding on this matter. Please know that we'll do our best to get this resolved.