QB Issue Resolution:

You may install Pro on the same machine as the Accountant’s version as long as Pro is a year other than 2011. (If it is 2011, you can just open the Pro file with the Accountant’s version.) Just be sure that during installation you choose Custom installation and install Pro in a different directory.

Resolution for Issue 'How do I go from Accountant 2011 to QB Pro?' available: Yes (Solved).
Source: Intuit Community forum.

How do I go from Accountant 2011 to QB Pro?: this 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 issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for Other
Quickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!

Error Recovery for Other [Canada]
E-Tech is the #1 Quickbooks data migration and Conversion service provider.

Get 50% off Quickbooks Online

Click Here for 50% off!

Additional Support Options: