<b><a href="https://www.quickbooksphonenumber.com/blog/resolve-quickbooks-wont-open-issue/">QuickBooks won't open</a></b> due to several reasons such as poor internet connectivity, outdated software, issues with the financial institution, or incorrect login credentials. First, confirm that your internet connection is sturdy and up-to-date. Then, update QuickBooks to the latest version, and reset the bank feed. If the issue persists, contact the financial institution to verify the login credentials and the account status. Try resetting the account in QuickBooks, and disabling and enabling the bank feed.