diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 50f50ff31..24142e0ec 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -9716,7 +9716,16 @@ scriptwait:
 
 	if (runaway != 0 && InModuleScriptNumber >= 0)
 	{
-		activeBehavior->GetScriptPtr(InModuleScriptNumber)->ProfileData.AddRun(runaway);
+		auto scriptptr = activeBehavior->GetScriptPtr(InModuleScriptNumber);
+		if (scriptptr != nullptr)
+		{
+			scriptptr->ProfileData.AddRun(runaway);
+		}
+		else
+		{
+			// It is pointless to continue execution. The script is broken and needs to be aborted.
+			I_Error("Bad script definition encountered. Script %d is reported running but not present.\nThe most likely cause for this message is using 'delay' inside a function which is not supported.\nPlease check the ACS compiler used for compiling the script!", InModuleScriptNumber);
+		}
 	}
 
 	if (state == SCRIPT_DivideBy0)