Can I use Vault Inventory for single player?

Yes. By default it is already setup for Offline only. See the How To for networking for help on setting up online multiplayer.

Why can't others join my game?

Probably because NAT. Yeah, the internet is a scary place.
If you made a build, gave it to a friend, gave him your IP and the correct Port number, both of you ran the build and he cannot connect then it is most likely a NAT punchthrough issue. You have to manually open the port on both routers, run dedicated servers or get a NAT Punch solution.
Every multiplayer game has to handle this at some point and there are a bunch of ways to do it. The Transport is basically what does this for you in Mirror. If you're deploying on Steam then the FizzySteamworks transport can handle it for you. Otherwise, you'll need a different solution or transport.
​Mirror Transports​
​More Info​

Can I use a different Network Transport?

Yes. We don't do anything at the transport level so that's all up to you.

Can I move the Vault Folder in the Hierarchy?

Yes. But it is not recommended.

How do I get Vault Data?

Use the [AssetDropdown(typeof(T))] attribute on any serialized field that derives from DataEntity, then pick the vault data you want in the inspector. That field is now a reference to that vault data.
The Getting Started video explains this. (Link below)

Can I change characters mid-game?

Yes. But, this doesn't actually have anything to do with Vault tools.
If you wanted to "Change characters" in some sense, you only need to confirm that the client has authority over the object and that the InventoryUi is pointing at the correct Inventory component.

The latest update causes compiler errors!

Oh noes!
You are generally safe deleting everything except the /Cleverous/Vault/Storage/ folder and reimporting fresh. You definitely don't want to delete that folder because that is where your data files are.
If you still have errors, the Unity version may have bumped up because we needed access to some new API and it's not in your Unity version. Update Unity or rollback with your Version Control.
If anything weird happens after reimporting, there are some functions to help fix things in the Tools>Cleverous> dropdown menu. If you're nervous, just jump on Discord and we can help on the spot.

Can I use Generics?

Basically no. We'll look into supporting this if possible in the future.

Vault has an error and doesn't load!

Try Cleverous > Vault > DB Soft Reload.
The other tools may be useful too, but usually if something gets stuck in the cache of Types then it can fail to load and needs a soft reload. If you still have issues, jump on Discord for support.