Our recent update includes password controls to verify that the person attempting to access an account is authorized.  Please see this article for more information: https://community.intuit.com/articles/1370759-quickbooks-desktop-security-information

Resolution for 'change password issue: 'QB Pro 2016, how do you turn off the change password every 90 days and complex passwords? No CC are used and protection is disabled???' available: Yes.

The change password issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the change password issue yourself by looking for a resolution described in the article. If it is a complex change password issue or you are unable to solve the issue, you may contact us by clicking here or by using other change password support options.

For more information about resolving issues related to change password in Quickbooks/QBO or to get support for the issue 'QB Pro 2016, how do you turn off the change password every 90 days and complex passwords? No CC are used and protection is disabled???', click the link below: