Let's get rid of the error so you create a statement to your customer, asettegast.

You can start by accessing your QuickBooks Online (QBO) account via a private browser. This is a great way to isolate the issue since it doesn't store data in the cache. Here are the keyboard shortcuts below:

• Google Chrome: CTRL + Shift + N 
• Mozilla Firefox and Internet Explorer: CTRL + Shift + P
• Safari: Command + Shift + N.

Once open, go back to the Customers tab from the Sales menu. Then, create your statements again. 

If it works, clear cache and cookies on your regular browser. If not, I suggest using other supported browsers to isolate this issue.

If you're getting the same error, I recommend contacting our QBO Support Team. They can create a case and send it to our Product Team for further investigation.

I'm just a post away if you need anything else. Thank you and take care always!