Ok! So make sure of these things:
1 - Eli book must be somewhere above all other Eli Plugins.
2 - Make sure you are using the right versions for your RPG Maker. For MZ, the plugin names always start with EliMZ_PluginName... So make sure you are using the MZ plugins for MZ and not for MV.
3 - You can also check my sample project to understand and test all the plugins.
If none of the above works, create a sample project replicating the error, and send it to me here or through my discord: hakuenstudio