QB Issue Resolution:
Start a new file using File->New. It won’t overwrite your old file unless you name the file the exact same thing as the old one. Even if you did that it will present a warning before allowing it that you have to accept.
You may want to search your drive for your original file. In the Finder, click on the spotlight icon in the upper right of the screen (its a magnifying glass). Type .qb2012. It should show you a list of files. All QuickBooks Mac 2012 files end with the file extension “.qb2012”. You may see your old file there.
Resolution for Issue 'I’m trying to start a new company in QuickBooks and it has taken over my old company name. lost data.' available: Yes (Solved).
Source: Intuit Community forum.
I’m trying to start a new company in QuickBooks and it has taken over my old company name. lost data.: 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 Company
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