Hi there, tocleo,
I can add some information about importing your QuickBooks Desktop data to QuickBooks Online.
Since you're unable to access your QuickBooks 2014 file in High Sierra, we can use the QuickBooks Mac 2019 trial version to open your company file and extract your data for import. Here's where you can access the Mac 2019 trial link: QuickBooks Desktop Trial Links
Once downloaded, make sure it is updated to the latest release to avoid migration errors. To update QuickBooks Desktop for Mac, please see Update QuickBooks Desktop to the latest release.
To export your Mac file, please follow the steps below:
- Open your company file and login as Admin.
- Go to the File menu.
- Select Export to QuickBooks Online.
- After the export, connect to your QuickBooks Online account using your userID and password.
- Click Sign In.
- Click OK, got it on the prompt.
- You'll get an email confirmation within 24 hours once the import is complete.
That's should get you back on track, tocleo. To know more about the conversion process, please check out this article: Convert QuickBooks Desktop for Mac file into QuickBooks Online
Please feel free to get me in the loop if you have any more questions about your QuickBooks file. I'm here to lend you a helping hand anytime.