diff --git a/Troubleshooting.md b/Troubleshooting.md
index 863b8ef..0a661d1 100644
--- a/Troubleshooting.md
+++ b/Troubleshooting.md
@@ -1,5 +1,19 @@
 # Program won't start
 
+## Re-running application does nothing
+
+There's a [bug](https://github.com/EDCD/EDMarketConnector/issues/678)
+we're trying to nail down where sometimes the application doesn't close
+cleanly.  The GUI application checks if there is still another instance of it,
+and if it finds one it just exits.
+
+In a version after 4.1.3 we'll be adding some logging, and possibly a pop-up,
+so it's obvious when this happens.
+
+In either case if you experience this then use Task Manager to double-check
+there isn't a lingering EDMarketConnector.exe process.  If so, forcibly kill
+it.
+
 ## Last logged "Locale LC_ALL: ..."
 
 If you're using EDMC 4.1.0 or later (including betas) you might find the