diff --git a/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/OnlineCheckProvider.kt b/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/OnlineCheckProvider.kt
index 9aae8628..6e26db3c 100644
--- a/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/OnlineCheckProvider.kt
+++ b/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/OnlineCheckProvider.kt
@@ -93,6 +93,16 @@ class OnlineCheckProvider(
                 res.type = TicketCheckProvider.CheckResult.Type.INVALID
             } else {
                 val response = responseObj.data!!
+
+                if (responseObj.response.code == 400 && !response.has("status")) {
+                    if (response.has("lists")) {
+                        // Kind of a special case handling, but regular problem for users and just
+                        // passing through the error messages from the server is not generally helpful
+                        // since user's don't know what a primary key is etc
+                        throw CheckException("Check-in list not found")
+                    }
+                }
+
                 val status = response.getString("status")
                 if ("ok" == status) {
                     res.type = TicketCheckProvider.CheckResult.Type.VALID
diff --git a/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/ProxyCheckProvider.kt b/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/ProxyCheckProvider.kt
index 2671eeac..81ac73c0 100644
--- a/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/ProxyCheckProvider.kt
+++ b/libpretixsync/src/main/java/eu/pretix/libpretixsync/check/ProxyCheckProvider.kt
@@ -150,7 +150,9 @@ class ProxyCheckProvider(private val config: ConfigStore, httpClientFactory: Htt
             e.printStackTrace()
             TicketCheckProvider.CheckResult(TicketCheckProvider.CheckResult.Type.ERROR, e.message)
         } catch (e: CheckException) {
-            TicketCheckProvider.CheckResult(TicketCheckProvider.CheckResult.Type.ERROR, e.message)
+            val r = TicketCheckProvider.CheckResult(TicketCheckProvider.CheckResult.Type.ERROR, e.message)
+            r.reasonExplanation = e.message
+            r
         }
     }