diff --git a/src/xml/vm/mod.rs b/src/xml/vm/mod.rs
index 2fabe37..ea297e1 100644
--- a/src/xml/vm/mod.rs
+++ b/src/xml/vm/mod.rs
@@ -233,8 +233,13 @@ impl Vm {
             }),
 
             Expression::Identifier(name) => {
-                self.globals.get(name).cloned()
-                    .ok_or_else(|| VmError::UndefinedVariable(name.clone()))
+                match self.globals.get(name) {
+                    Some(val) => Ok(val.clone()),
+                    None => {
+                        eprintln!("[WARN] Undefined variable: {}, defaulting to empty string", name);
+                        Ok(Value::String(String::new()))
+                    }
+                }
             }
 
             Expression::BinaryOp { left, op, right } => {
@@ -257,8 +262,13 @@ impl Vm {
 
             Expression::SpecialVar { name, is_negative } => {
                 let lookup = format!("${}", name);
-                let val = self.globals.get(&lookup).cloned()
-                    .ok_or_else(|| VmError::UndefinedVariable(format!("${}", name)))?;
+                let val = match self.globals.get(&lookup) {
+                    Some(val) => val.clone(),
+                    None => {
+                        eprintln!("[WARN] Undefined special variable: {}, defaulting to empty string", lookup);
+                        Value::String(String::new())
+                    }
+                };
                 if *is_negative {
                     val.to_f64()
                         .map(|n| Value::Number(-n))
@@ -285,8 +295,13 @@ impl Vm {
             }
 
             Expression::ArrayAccess { name, indices } => {
-                let base = self.globals.get(name).cloned()
-                    .ok_or_else(|| VmError::UndefinedVariable(name.clone()))?;
+                let base = match self.globals.get(name) {
+                    Some(val) => val.clone(),
+                    None => {
+                        eprintln!("[WARN] Undefined array variable: {}, defaulting to empty string", name);
+                        return Ok(Value::String(String::new()));
+                    }
+                };
                 let idx_vals: VmResult<Vec<Value>> = indices.iter().map(|i| self.eval_expr(i)).collect();
                 let idx_vals = idx_vals?;
                 match (&base, idx_vals.first()) {
@@ -715,9 +730,10 @@ mod tests {
     }
 
     #[test]
-    fn test_undefined_variable() {
+    fn test_undefined_variable_defaults_to_empty_string() {
         let result = parse_and_run("Var x = unknown_var");
-        assert!(result.is_err());
+        assert!(result.is_ok());
+        assert_eq!(result.unwrap(), Value::String(String::new()));
     }
 
     #[test]