So I have a few plugins that I have made and they seem to work perfectly until the server is restarted, here is the info:

I hook OnEntityBuilt and if its my plugin's I attach my subclass which is a MonoBehavior to it by using AddComponent<>. These are things that are meant to stay in the world. The problem is that when the server is restarted, it seems like the the component isn't there anymore? It stops working.

Any ideas?

It does because all the components that you adding manually aren't saving after the server restarted.
You need to add them again when the server is initialized. Probably you need to save all these entities as a data file as well.

Ah ok and no way to save them this must be done on initialize. Thanks for the the reply! It has been a while, could you please remind me of the call to find all entities that are in the world by type? Like for example to find all the recyclers isnt there something like FindAllByType<Recycler> or something like that, it has been while and I'm struggling to remember.

Also, why would I need to save them in a data file? They are still in the proper location after server restart and all that, they just do not function.

You said you are using OnEntityBuilt for adding these components, so I guess you don't need to find all the entities in the world, you at least not interested in a bunch of entity types like trees, animals, you know.
But if you do, you can use BaseNetworkable.serverEntities to go through all of them or if you want to find certain entities by the type, try to use GameObject.FindObjectsOfType<T>()

Oh ok! I see what you meant by using the data file now so that I know which ones need "fixed" without searching through things! Thank you! I'm going to have to try and test some things to see how exactly to fix this, I know what needs doing just not sure how to put it into code yet. But thank you for the help! Back to coding I go!