I've checked and no reported issue similar to this, james51.
This can be caused by too much stored files in your browser. To check if this is the case, let's try a few basic troubleshooting steps:
If you're still getting the same error, I'd suggest reaching out to our phone support team so they can investigate this further.
I'll be around if you have other concerns.
I was getting a very similar error message yesterday and in sheer frustration resorted to "turn it off and turn it on again". Not the computer just QB. Error message went away.