I tried exporting a report in excel and this message occured {"message" :"Unexpected Internal Error. (-30006)" ,"code" :-30006}. What goes wrong?

I can help you sort this out, techsupport-pahi.

First, to isolate the issue as browser-related, please access your account using a private or incognito browser window. Use these keyboard shortcuts:

• Ctrl+ Shift + N for Google Chrome 
• Ctrl + Shift + P for Mozilla Firefox and Microsoft Edge 
• Command + Shift + N for Safari

After logging in, attempt to export the report to Microsoft Excel once again. If the error is no longer visible, you may need to clear the cache of your regular browser. Additionally, consider using another supported web browser to further isolate the issue.

If the issue persists, I'd recommend contacting our Customer Support team. A specialist can further look into the error and determine its root cause and resolution. 

Here's how:

1. Sign in to your QuickBooks Online.
2. Choose Help (?).
3. Click on either tab to get started:
   • Assistant: To get quick, personalized answers. Add the topic you need help with. If you need further help, you can still Talk to a human.
   • Search: To search on the QuickBooks Online knowledge base directly, choose Contact Us and select a way to connect with us:
     • Start a chat with a support expert.
     • Get a callback from the next available expert.
     • Ask the community to get help from businesses like yours.

I'd also recommend checking on this article to help you how to run reports in QuickBooks Online.

Please don't hesitate to contact the community if you need further assistance. I am always here to help. Have a great day!