docs: Improve troubleshooting solutions (#1543)

Co-authored-by: oSumAtrIX <[email protected]>

docs/3_troubleshooting.md

@@ -5,14 +5,16 @@ In case you encounter any issues while using ReVanced Manager, please refer to t
 - 💉 Patching fails with an error
 
   Make sure ReVanced Manager is up to date by following [🔄 Updating ReVanced Manager](2_3_updating.md) and select the **Default** button when choosing patches.
-  
+
 - 🚫 App not installed as package conflicts with an existing package
 
-  An existing installation of the app you're trying to patch is conflicting with the patched app. Uninstall the existing app before installing the patched app.
+  An existing installation of the app you're trying to patch conflicts with the patched app (i.e., signature mismatch or downgrade). Uninstall the existing app before installing the patched app.
 
 - ❗️ Error code `135`, `139` or `1` when patching the app
 
-  Your device is not supported. Refer to the [Prerequisites](0_prerequisites.md) page for supported devices.
+  You may be trying to patch a split APK[^1]. This may not work under certain circumstances. In such a case, patch a full APK.
+
+  Your device may otherwise be unsupported. Please look at the [Prerequisites](0_prerequisites.md) page for supported devices.
 
   Alternatively, you can use [ReVanced CLI](https://github.com/revanced/revanced-cli) to patch the app.
 
@@ -25,3 +27,5 @@ In case you encounter any issues while using ReVanced Manager, please refer to t
 The next page will teach you how to build ReVanced Manager from source.
 
 Continue: [🔨 Building from source](4_building.md)
+
+[^1]: https://developer.android.com/guide/app-bundle/app-bundle-format