QB Issue Resolution:

If you know they manually confirmed everything and it is Perfect, sure, you can make any leap you want. You don’t even have to do Annual. Just go to Jan 2018, perhaps, in one jump.

Resolution for Issue 'bank reconciliation CLIENT has used software for many years and have never done the bank in QB, how do I start? I believe 2007 forward on data. Thank you!' available: Yes (Solved).
Source: Intuit Community forum.

bank reconciliation CLIENT has used software for many years and have never done the bank in QB, how do I start? I believe 2007 forward on data. Thank you!: 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 Bank Reconciliation
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Error Recovery for Bank Reconciliation [Canada]
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