Hi there, @Roland12.

I do appreciate your time and effort in performing the troubleshooting steps provided by my colleague in this thread. I wish you didn't have to go through all these hurdles when opening a pdf. 

I can see that you've been promised a callback and escalation. Please know that there’s an ongoing investigation about previewing pdf document. 

I checked our resources and see that our team is actively working on your case. Since this is also a reported issue, I recommend contacting our Support Team again. This way, you’ll be added to the list of affected users so you’ll get notified of the progress. 

Here’s how:

1. Go to the Help icon.
2. Select the Search tab and click Contact Us.
3. Enter a brief description of your concern.
4. Hit Continue.

Here’s an article you can read adding attachments to customer and vendor profiles, as well as their transactions: Add or delete attachments in QuickBooks Online.

If you need help with navigating your QBO company, you can visit our website for tips and other resources for reference: QuickBooks Help articles. This will help you in managing your income, expenses, banking, inventory, and running reports.

Shoot me a reply if have any other pdf concerns or you need any other QuickBooks help. We're just around to assist you.