2014 is not Sierra compatible. Also, the 2012 version isn’t compatible with Sierra either.
You can download the 2016 trial version from the following web site.
Resolution for '2012 version issue: 'Quickbooks 2012 to Quickbooks Online?' available: Yes.
The 2012 version 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 2012 version issue yourself by looking for a resolution described in the article. If it is a complex 2012 version issue or you are unable to solve the issue, you may contact us by clicking here or by using other 2012 version support options.
For more information about resolving issues related to 2012 version in Quickbooks/QBO or to get support for the issue 'Quickbooks 2012 to Quickbooks Online?', click the link below: