You may need to use the converter kit.

Download and install the upgrader’s kit (QuickBooks 2006)

Click here to download our upgrader’s kit and save the .exe file in a temporary location on your computer.
This upgrader’s kit is a special trial version of QuickBooks 2006. It’ll ask you to […]

Resolution for 'conversion finishes issue: 'How to upgrade Company File from Older Version?' available: Yes.

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

For more information about resolving issues related to conversion finishes in Quickbooks/QBO or to get support for the issue 'How to upgrade Company File from Older Version?', click the link below: