Unfortunately, The Journal 5 doesn’t work with Windows 10. (NOTE: This *only* affects The Journal 5.)
To continue using The Journal after you upgrade to Windows 10, you will need to upgrade to The Journal 7. You can download The Journal 7 from here to install it. The first time you run The Journal 7, it should offer to upgrade you existing entries. Let it.
As a registered user of The Journal 5 you are eligible for upgrade pricing. See here for more information.
If you have any questions, please don’t hesitate to ask: support@davidrm.com
-David