Merge pull request #4018 from segmentio/daldeano-segment-facebook-lead-ads-patch-1-1

What to do when credentials have updated/changed

Author: daldeano-segment

src/connections/sources/catalog/cloud-apps/facebook-lead-ads/index.md

@@ -133,3 +133,12 @@ Destinations that can be used with the Facebook Lead Ads Source:
 - Madkudu
 
 Log into your downstream tools and check that your events are populating, and contain all of the properties you expect. If all your events and properties are not showing up, refer to the [Destination docs](https://segment.com/docs/connections/destinations/) for troubleshooting.
+
+
+## Troubleshooting
+
+### No Data After Updating Credentials
+
+When a connected account changes or updates their credentials, the customer will have to create a new Facebook Lead Ads source. Reauthorization implies that a new token gets generated, but the token is not the sole link between Segment and Facebook. A Segment app is installed onto an FB Account and that will be the sprouting point from where tokens are generated. The reason we can't disconnect and reconnect the CRM on Facebook with reauthorization is because the creation of a new token will mean to invalidate the rest of the tokens attached to the same Facebook account. 
+
+For example, let's imagine you have a Facebook Account with three accounts: Account A, Account B, and Account C. You connect Segment to all of them and then generate tokens respectively. Later on, you decide for whatever reason to reauthorize the "Account A" page, the other tokens will be invalidated, and the pages will stop working.