QBO Project Estimate over 100 lines. Will not load to create invoice. How can I create the invoice from the estimate if it will not load in any browser?

Hi, Stephanie. We appreciate your efforts in resolving the issue by performing troubleshooting steps.

The problem is likely caused by an overload of data in the system. Allow me to provide you with alternative steps to complete your task.  

You can use the progress invoicing feature and add estimates to your progressive invoices. This will keep your customers informed and updated on how much they’ve spent on their projects. You can begin by converting half of the estimates to avoid any errors.

Here's how:

1. Turn on progress invoicing. 
2. Go to the Gear icon and select Custom form styles.
3. Choose Edit on the template you use for progress invoicing.
4. Open the Content tab, then click the Edit icon on the third section of the form.
5. Tick the Estimate summary checkbox, then hit Done.
6. Go to the + New menu, then choose Invoice.
7. From the Customer dropdown, select the customer you created an estimate for.
8. From the Add to Invoice section, choose Add on the estimate you want to add to the invoice.
9. Choose the option on how much you want to invoice, then click Copy to invoice.
10. Select Customize, then pick the template you use for progress invoicing. Hit Save.

For more detailed information regarding the process, you can refer to this article: Add project estimate summaries to a progress invoice in QuickBooks Online.

In case you want to personalize and add specific info to your sales forms, you can check out this article for guidance: Customize invoices, estimates, and sales receipts in QuickBooks Online.

You can get back to this thread if you have any other concerns besides creating an invoice from an estimate. The Community is always around to help you out.