Currently Bookshelf crashes on the latest versions of Forge upon startup.

Minecraft Version: 1.19
Forge Version: 41.0.94
Mod Version: 14.0.3

Crash Log: https://mclo.gs/xRPiavw

Hello, this is a broader issue caused by Forge making breaking changes to their APIs mid-version. Many mods including Bookshelf will need to update to account for these changes. They only made these changes 5 hours ago, so mod authors will need some time to update everything.

The 14.1.7 release of Bookshelf should be compatible with your version of Forge. I will make my way through the rest of my mods this week.