If you don’t mind, could you please provide a screenshot of what occurs when trying to add an account? If needed, please refer to this Community FAQ for instructions on how to attach a screenshot. Alternatively, you can also drag and drop screenshots to your response if you are not given the option to add attachments.
Looking forward to hearing your response.
Close Quicken, remove the “Cache” folder from “C:\ProgramData\Quicken”, then reopen Quicken.