⚡ Display errors in expressions

packages/editor-ui/src/components/ExpressionInput.vue

@@ -166,11 +166,11 @@ export default mixins(
 				let returnValue;
 				try {
 					returnValue = this.resolveExpression(`=${variableName}`);
-				} catch (e) {
-					return 'invalid';
+				} catch (error) {
+					return `[invalid (${error.message})]`;
 				}
 				if (returnValue === undefined) {
-					return 'not found';
+					return '[not found]';
 				}
 
 				return returnValue;