You can try copying the company file from the jump drive to your documents folder. In the end youll need to upgrade to QB to 2015, thats the only year version supported on Yosemite.

Resolution for 'Cocoa issue: 'What is Cocoa error 21?' available: Yes.

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

For more information about resolving issues related to Cocoa in Quickbooks/QBO or to get support for the issue 'What is Cocoa error 21?', click the link below: