Kindly follow these steps:
- Take backup of your data in SD card/email/Pendrive/External drive (Just in case)
- Close Book Keeper
- Download new update from this link: bookkeeperapp.net/download
- Install new update
- Open Book Keeper it has been updated now.
how to update Book Keeper Windows: https://www.youtube.com/watch?v=aCPjnGo7c9s
how to update Book Keeper Mac: https://www.youtube.com/watch?v=jXqkYKS4r0k