diff --git a/Known-Issues-and-Workarounds.md b/Known-Issues-and-Workarounds.md
index 7db17b9..61cf7ba 100644
--- a/Known-Issues-and-Workarounds.md
+++ b/Known-Issues-and-Workarounds.md
@@ -1,3 +1,11 @@
+## Important Note
+
+If you have previously installed `Daggerheart: Core`, also known as `Unofficial Daggerheart` it will break a lot of things. Only one of the systems can be installed, since that system chose the same system ID as our system, despite having a different Display name and Package ID.
+
+You also have to recreate any actors (including adversaries) and icons wit the new system. We recommend to also create a new world, just to make sure.
+
+***
+
 ## Issue title
 
 Issue description  text