Document the Duplicate MAC error some users experience when a pod is not correctly discarded/de-activated

docs/EN/CompatiblePumps/OmnipodDASH.md

@@ -574,6 +574,18 @@ To remove the old pod session:
 3. After the second or third retry you will get the option to remove the pod. 
 4. Once the old pod is removed you will be able to activate a new pod.
 
+### Generic error: java.lan.illegalStateException: Trying to set a Bluetooth Address to ***, but it is already set to ***.  
+
+If you receive this error when attempting to Initialize a new pod **AAPS** fails as it still has settings for an old pod stored in configuration. 
+
+![omnipod_address_in_use](../images/DASH_images/Errors/omnipod_address_in_use.png)
+
+This can happen if you restore from a backup, or a pod deactivation fails.
+
+To resolve keep clicking on `RETRY` until a `Discard` option is shown, then discard. This procedure should work for De-Activating a pod too.
+
+You should now be able to Activate a new pod.
+
 ---
 ### Reinstalling AAPS