diff --git a/Troubleshooting.md b/Troubleshooting.md
index 3e9da54..9e0d7fb 100644
--- a/Troubleshooting.md
+++ b/Troubleshooting.md
@@ -1,7 +1,18 @@
 ### Can't Update - "Invalid Credentials"
 Some people find that they can log-in and receive a verification code from Frontier. But on hitting the Update button they see an "Invalid Credentials" error.
 
-It's not clear why this happens to some people, but it does seem to happen more often to people who purchased Horizons without Season 1.
+If you've purchased Horizons (without Season 1) **on Steam** you may be able to solve this error by:
+
+* Logging on to Steam.
+* Check that you have both an Elite:Dangerous and Horizons DLC key.
+* In the [Partner Keys](https://www.frontierstore.net/eur/frontier_partnerkeys/) section of the Frontier Store add the base Elite: Dangerous key.
+
+If you've purchased Horizons (without Season 1) from **the Frontier store** you may be able to solve this error by:
+
+* Registering with / logging on to Steam.
+* In the [Partner Keys](https://www.frontierstore.net/eur/frontier_partnerkeys/) section of the Frontier Store link your your Frontier account to your Steam account.
+* Note that you can still play Horizons using your exisiting launcher and Frontier login.
+
 
 This problem is tracked as [Issue #43](https://github.com/Marginal/EDMarketConnector/issues/43).