Trying to save data just entered into a JE but I get an error message " select an account for this transaction but all account lines are filled.? Pls advise?

Welcome to the Community, @ghabelt.

I'd be glad to help and provide some insights into why you're getting an error message upon entering data into Journal Entry in QuickBooks Online (QBO).

To start, if a line in the Journal Entry is missing an account, you will receive an error message. However, since you have already filled in the required accounts and the issue persists, I recommend trying some troubleshooting steps to determine whether the issue is related to your browser.

To maintain your privacy, please open a new incognito window. This will prevent your browser from saving your browsing history. You can open an incognito window using the following keyboard shortcuts based on the browser you are using:

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

If the private browsing session works, you can clear the browser's cache to improve the program's performance. You can also use other supported, up-to-date browsers as an alternative which will provide the best and most secure experience with QuickBooks.

For future reference, you can check this article to guide you about Reconcile workflow so you can review your accounts in QuickBooks Online.

Please don't hesitate to leave a comment below if have further concerns about Journal Entry or other QBO-related concerns. I'll be happy to assist you.