Trying to import my data from desktop to QBO:Error: beanstalk.zlib generation failed" I already rebuilt the QB file and have tried importing twice. What is wrong?

How big is the Total Target? More than 350K? 

Thank you for reaching out to the QuickBooks Community, @jwenzel. I appreciate you bringing this matter to our attention.

Upon checking, I've found out that there's an ongoing issue with importing data from QuickBooks Desktop to QuickBooks Online. Our dedicated team of engineers is actively working on resolving this concern to ensure a smooth transition for you.

If you haven't contacted our phone support yet, I'd suggest doing so. By contacting them, you can have your account added to the list of affected users, ensuring that you receive prompt notification as soon as the issue is resolved.

Here's how to connect with them:

1. Go to Help and select QuickBooks Desktop Help/Contact Us.
2. Click Contact Us.
3. Give a brief description of your issue, then select Continue.
4. Sign in to your Intuit account and click Continue, then select Continue with my account.
5. We'll email you a single use code. Enter your code and select Continue.
6. Choose chat with us or Have us call you.

In addition, after you successfully transfer your files, you may notice differences in how your books appear. To help you understand how your books were moved, please see this article: Learn how features and data move from QuickBooks Desktop to QuickBooks Online.

If you have any other questions or concerns unrelated to your QuickBooks experience, please don't hesitate to let me know. Click the Reply button to leave a comment below. Your satisfaction is our priority. Take care and stay safe!

Update: Spoke with a customer service agent via QBO chat and it worked. I can't explain why because it was the exactly same process I did last night. But this question is now resolved.