diff --git a/drools-workbench-models/drools-workbench-models-commons/src/main/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceImpl.java b/drools-workbench-models/drools-workbench-models-commons/src/main/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceImpl.java
index 0afed30c56e..51385d973ce 100644
--- a/drools-workbench-models/drools-workbench-models-commons/src/main/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceImpl.java
+++ b/drools-workbench-models/drools-workbench-models-commons/src/main/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceImpl.java
@@ -2350,6 +2350,16 @@ private RuleDescr parseDrl(final ExpandedDRLInfo expandedDRLInfo) {
         return packageDescr.getRules().get(0);
     }
 
+    private RuleDescr parseDrl(final String drl) throws DroolsParserException {
+        final DrlParser drlParser = new DrlParser();
+        final PackageDescr packageDescr = drlParser.parse(true, drl);
+        if (drlParser.hasErrors()) {
+            throw new RuleModelUnmarshallingException();
+        }
+
+        return packageDescr.getRules().get(0);
+    }
+
     private boolean parseAttributes(final RuleModel m,
                                     final Map<String, AttributeDescr> attributes) {
         boolean isJavaDialect = false;
@@ -2701,6 +2711,10 @@ private CompositeFactPattern parseExistentialElementDescr(final RuleModel m,
                                                               final boolean isJavaDialect,
                                                               final Map<String, String> boundParams,
                                                               final PackageDataModelOracle dmo) {
+        if (conditionalDescr.getDescrs().stream().anyMatch(d -> d instanceof ConditionalElementDescr)) {
+            throw new RuleModelUnmarshallingException();
+        }
+
         CompositeFactPattern comp;
         if (conditionalDescr instanceof NotDescr) {
             comp = new CompositeFactPattern(CompositeFactPattern.COMPOSITE_TYPE_NOT);
@@ -4348,12 +4362,18 @@ public static class RuleModelUnmarshallingException extends RuntimeException {
     }
 
     //Simple fall-back parser of DRL
-    public RuleModel getSimpleRuleModel(final String drl) {
+    private RuleModel getSimpleRuleModel(final String drl) {
         final RuleModel rm = new RuleModel();
         rm.setPackageName(PackageNameParser.parsePackageName(drl));
         rm.setImports(ImportsParser.parseImports(drl));
 
-        final Pattern rulePattern = Pattern.compile(".*\\s?rule\\s+(.+?)\\s+.*",
+        try {
+            parseAttributes(rm, parseDrl(drl).getAttributes());
+        } catch (Exception e) {
+            //Discard. We're unable to retrieve the rule attributes from the DRL
+        }
+
+        final Pattern rulePattern = Pattern.compile(".*\\s?rule\\s+\"(.+?)\"\\s+.*",
                                                     Pattern.DOTALL);
         final Pattern lhsPattern = Pattern.compile(".*\\s+when\\s+(.+?)\\s+then.*",
                                                    Pattern.DOTALL);
diff --git a/drools-workbench-models/drools-workbench-models-commons/src/test/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceUnmarshallingTest.java b/drools-workbench-models/drools-workbench-models-commons/src/test/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceUnmarshallingTest.java
index 8d75c98e268..bca5f9b9055 100644
--- a/drools-workbench-models/drools-workbench-models-commons/src/test/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceUnmarshallingTest.java
+++ b/drools-workbench-models/drools-workbench-models-commons/src/test/java/org/drools/workbench/models/commons/backend/rule/RuleModelDRLPersistenceUnmarshallingTest.java
@@ -9696,4 +9696,33 @@ private void assertSingleFieldConstraintOperatorNoSpace(final String operator) {
         assertEquals(BaseSingleFieldConstraint.TYPE_LITERAL,
                      sfp.getConstraintValueType());
     }
+
+    @Test
+    public void testNestedOr() {
+        final String drl = "rule \"my rule\"\n" +
+                "dialect \"mvel\"\n" +
+                "when \n" +
+                "(\n" +
+                "   (\n" +
+                "      Term(effectiveDate < \"30-Sep-2018\") and \n" +
+                "      Policy($state : state == \"KS\" || == \"MN\" || == \"NM\" || == \"UT\")\n" +
+                "   )\n" +
+                "   or\n" +
+                "   (\n" +
+                "      Term(effectiveDate < \"23-Jun-2019\") and\n" +
+                "      ( \n" +
+                "         Policy(state == \"AZ\" || == \"IA\" || == \"NE\" || == \"SD\" )\n" +
+                "      ) \n" +
+                "   )\n" +
+                ") \n" +
+                "then \n" +
+                "end\n";
+
+        final RuleModel model = RuleModelDRLPersistenceImpl.getInstance().unmarshal(drl,
+                                                                                    Collections.emptyList(),
+                                                                                    dmo);
+
+        assertEqualsIgnoreWhitespace(drl,
+                                     RuleModelDRLPersistenceImpl.getInstance().marshal(model));
+    }
 }