I successfully downloaded GnuCash and linked it with my Quicken data files. But now all my account information is scrambled--bank balances up or down by an order of magnitude, securities sold long ago now showing up, and "categories" mixed up with "accounts." GnuCash states that opening balances are "noneditable" so I'm stuck at the moment. What's the solution? Should I reinstall, set everything at zero and start over, or is there a simpler way to match this up with our previous Quicken entries.
While this is more of a software question and will probably be closed, I would say that yes you probably need to start again fresh. You won't need to reinstall the software, just create a new account book and import the data again. However, before you do this the second time, take a moment to read up on the process. See if there was something that was incorrect during your first attempt. There are many good quality guides online, along with the core documentation. Review some of those and make sure you're checking the right boxes when you do the import.