It must be an Intuit issue.  Even though the Intuit server site says operational, too many people at once are experiencing the same problem for it not to be a QB problem.

Resolution for '404 page issue: 'WHen i click on a bank account on the DAshboard page it says 404 page not found' available: Yes.

The 404 page 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 404 page issue yourself by looking for a resolution described in the article. If it is a complex 404 page issue or you are unable to solve the issue, you may contact us by clicking here or by using other 404 page support options.

For more information about resolving issues related to 404 page in Quickbooks/QBO or to get support for the issue 'WHen i click on a bank account on the DAshboard page it says 404 page not found', click the link below: