Hello @andyf123
Thank you for reaching out on the community and telling us about your issue. I do apologize for the issue you're having. I was taking a look to see if I could also was able to get the same error but was not able to. If you wouldn't mind could we try in a test file to see if we're able to also get the same error when trying to add the accounts to quicken. I'll leave steps down below.
Don't use any of these characters: * ? < > | " : \ / (asterisk, question mark, left and right-angle bracket, pipe, straight quotation marks, colon, BACKSLASH, FORWARD SLASH). Also, don't add the .qdf extension; Quicken does that for you.
After adding accounts, see if you are experiencing the same problems in this test file. Once you're able to let us know more we'll see what we can do.
Thanks,
Quicken Francisco
https://www.quicken.com/support#contact-support
When contacting support, be sure to let me know how long you have been receiving this error.
Let us know how it goes!
-Quicken Tyka