QB Issue Resolution:

the export to desktop from QBO provides you with a file that must be opened in desktop within 10 days, and the file has known problems, some things do not export, inventory exports as service items with no history, these known problems have existed for over 5 years
https://qboe.custhelp.com/app/answers/detail/a_id/1447
this link explains how
https://qboe.custhelp.com/app/answers/detail/a_id/6546

FYI
QBO does not have a back up at all from the user perspective.

Intuit backs the servers up, but can not restore your file from that back up

the make local copy provides you with a copy that does not contain all financial information, and can not be used locally, nor can it be used to upload to the old or a new QBO file
https://qboe.custhelp.com/app/answers/detail/a_id/1774/related/1

Resolution for Issue 'I am switching from quickbooks online to quickbooks pro 2015 at the request of my accountant. I need instructions on how I can make a backup of my registers.' available: Yes (Solved).
Source: Intuit Community forum.

I am switching from quickbooks online to quickbooks pro 2015 at the request of my accountant. I need instructions on how I can make a backup of my registers.: 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 Import
Quickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!

Error Recovery for Import [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: