Cause
A license key that is not valid for your operating system or version of Banana Accounting Software has been entered.
For Banana Accounting Plus no license key is necessary, as the subscription is based on the user's email. If you changed your email or in case of problems with the email please contact us.
Solution
Check which version the license key you have belongs to.
If you have an older version of Banana (version 9 or earlier), update to Banana Accounting Plus to avoid problems with license keys.