If you are running Minetest release 0.4.15 (December 2016), please use series 1.1.x from [past releases](https://github.com/taikedz/everamzah-books/releases), or track the v1.1.x branch instead of master; note that the 1.1.x series will no longer be updated since the release of Minetest 0.4.16.