In 2018 with the no company open screen in place, use open new company and browse to the company files and try it

I expect the company file is too old to directly load, if that is the case you will need to make a back up file and open it […]

Resolution for '2018 disc issue: 'How do I open 2010 backup R5 in USA 2018 disc' available: Yes.

The 2018 disc 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 2018 disc issue yourself by looking for a resolution described in the article. If it is a complex 2018 disc issue or you are unable to solve the issue, you may contact us by clicking here or by using other 2018 disc support options.

For more information about resolving issues related to 2018 disc in Quickbooks/QBO or to get support for the issue 'How do I open 2010 backup R5 in USA 2018 disc', click the link below: