Using it it crashes saying SuperPictures are undefined. Can't use the Picture Manager without it though and that one cost me 15 bucks.

Essential plugin for all Eli plugins in RPG Maker MV/MZ! · By
Hi there!
Yes, EliMZ_Book is my core plugin and all other EliMZ plugins need it. Make sure you have it somewhere above all other EliMZ plugins on your plugin manager.
Now, `superPictures` is the name of the object that holds all the EliMZ_PictureManager saved data. If you have installed both EliMZ_Book and EliMZ_PictureManager and you are getting this error, I guess maybe you installed the plugin and is trying to load a previous save file that did not have that plugin at the time. If that is true, you need to start a new game after install the Picture Manager.
Now you also need to give me more information:
1 - Are you suing RPG Maker MZ or MV?
2 - Are you using the latest RPG Maker MZ core files(version 1.10.0)?
3 - When the error happens, as soon as you hit playtest? When start a new game? When loading a save file?
4 - When the error happens, press F8 or F12. A browser window will open. Go to the CONSOLE tab, and send me a screenshoit of what is in there.
It's a common issue with the RPG Maker itself, not specifically to my plugin. It happens since MV. When you install a new plugin, that stores changes on the save file, you need to start a new game, otherwise you get a lot of errors. Some example of other people talking about it:
The save file does not understand when you do that, when you load it with a new plugin(that creates some data to be saved) that previous it did not have. Unfortunatelly you will need to start a new game to make it work.
BUT, I will see if somehow nowdays I can try to make a workaround for that. This is a common issues for years, since MV. Maybe there is a way to solve that... But I can promise you when I will do that.