# 6. Modding Pitfalls Part of [[Modding with Addressables]]. Prev: [[5. Worked Example Cosmetic Pack]]. ## Secondary project built as local content Official multi-project rule: local data from a secondary project **cannot** be loaded in the source player. Remote groups + **Build Remote Catalog**. ## Different Editor or Addressables versions between projects Official requirement: same Editor, same Addressables package. 2.9.1 vs a 4.x secondary catalog is how you get mysterious locator failures. ## `autoReleaseHandle` left false, update never appears Official: a cached load operation can prevent a new catalog download. Prefer `true`, and release before `UpdateCatalogs`. ## Updating while bundles are loaded Official conflict risk. Unique Bundle IDs or an unload pass. Not a silent background tick in `Update` (`UpdateCatalogs` blocks other Addressable requests). ## Built-in resource bundle name collision Official `The AssetBundle [bundle] can't be loaded because another AssetBundle with the same files is already loaded.` Set **Built In Bundle Naming Prefix** per project. ## "We'll just load a DLL from the catalog" Out of scope. Packs use types **already in the player**. Prefabs with unknown scripts will not magically compile. ## HTTP "just for class" left on for release Prefer HTTPS. Do not flip Allow downloads over HTTP to Always Allowed as a fix. ## IAP on the pack menu Out of scope, same as [[Publishing to itch.io and Steam]]. ## Forgetting to release instances The load/release contract in [[3. Loading Instantiating and Releasing]] still applies after a second catalog is in. You cannot unload the catalog itself; you can still leak instances. ## Assuming 4.2 APIs in a 2.9 project The 6000.5 page now lists **4.2.0** as available, but this series (and the Addressables series) stays on the **2.9 API**. No `ToAwaitable()` unless you upgraded on purpose. ## Sources - https://docs.unity3d.com/Packages/[email protected]/manual/MultiProject.html - https://docs.unity3d.com/Packages/[email protected]/manual/LoadContentCatalogAsync.html