Welcome to the QuickBooks Community, info-edubuild-de.
The error message you're getting occurs if you selected and incorrect Payment account when creating a transaction, example Expense.
In the sample screenshot below, you can't use a Current asset as the Account Type for an expense transaction. Instead, use a Cash and cash equivalents or Credit card.
If you're not sure which account to use, I suggest consulting your accountant. They can help guide and provide expert advise to make sure everything is accurate. Once you selected a different account, the error should no longer show up
I've got your back if you need more help. I'm always happy to lend a hand. Have a good one.