Great to know you're able to create an invoice on another browser, seb2.

Have you tried clearing the browser cache in an All time option? If not, let's try deleting the browser data in that time frame. Just follow the steps in this article: https://support.google.com/chrome/answer/2392709?hl=en.

Then, let's make sure Chrome is updated to the latest security updates. You can check out this article on how to update Google Chrome: https://support.google.com/chrome/answer/95414?co=GENIE.Platform%3DDesktop&hl=en.

Once done, try creating a new invoice using your default browser.

I've got a link here that contains articles about managing customers and income: https://quickbooks.intuit.com/learn-support/manage-customers-and-income/misc/02/uk-manage-customers-....

Feel free to come back to this thread if you need anything else with managing your invoices. I'll be here to help.