diff --git a/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/AnswerOption.jsx b/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/AnswerOption.jsx
index a0ee440b62..07d7130045 100644
--- a/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/AnswerOption.jsx
+++ b/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/AnswerOption.jsx
@@ -18,6 +18,7 @@ import { FeedbackBox } from './components/Feedback';
 import * as hooks from './hooks';
 import { ProblemTypeKeys } from '../../../../../data/constants/problem';
 import ExpandableTextArea from '../../../../../sharedComponents/ExpandableTextArea';
+import { answerRangeFormatRegex } from '../../../data/OLXParser';
 
 const AnswerOption = ({
   answer,
@@ -47,6 +48,11 @@ const AnswerOption = ({
     staticRootUrl = `${getConfig().STUDIO_BASE_URL }/library_assets/blocks/${ blockId }/`;
   }
 
+  const validateAnswerTitle = (value) => {
+    const cleanedValue = value.replace(/^\s+|\s+$/g, '');
+    return !cleanedValue.length || answerRangeFormatRegex.test(cleanedValue);
+  };
+
   const getInputArea = () => {
     if ([ProblemTypeKeys.SINGLESELECT, ProblemTypeKeys.MULTISELECT].includes(problemType)) {
       return (
@@ -78,8 +84,9 @@ const AnswerOption = ({
       );
     }
     // Return Answer Range View
+    const isValidValue = validateAnswerTitle(answer.title);
     return (
-      <div>
+      <Form.Group isInvalid={!isValidValue}>
         <Form.Control
           as="textarea"
           className="answer-option-textarea text-gray-500 small"
@@ -89,11 +96,15 @@ const AnswerOption = ({
           onChange={setAnswerTitle}
           placeholder={intl.formatMessage(messages.answerRangeTextboxPlaceholder)}
         />
+        {!isValidValue && (
+          <Form.Control.Feedback type="invalid">
+            <FormattedMessage {...messages.answerRangeErrorText} />
+          </Form.Control.Feedback>
+        )}
         <div className="pgn__form-switch-helper-text">
           <FormattedMessage {...messages.answerRangeHelperText} />
         </div>
-      </div>
-
+      </Form.Group>
     );
   };
 
diff --git a/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/messages.js b/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/messages.js
index 5f58109137..d69bc876d7 100644
--- a/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/messages.js
+++ b/src/editors/containers/ProblemEditor/components/EditProblemView/AnswerWidget/messages.js
@@ -77,6 +77,11 @@ const messages = defineMessages({
     defaultMessage: 'Enter min and max values separated by a comma. Use a bracket to include the number next to it in the range, or a parenthesis to exclude the number. For example, to identify the correct answers as 5, 6, or 7, but not 8, specify [5,8).',
     description: 'Helper text describing usage of answer ranges',
   },
+  answerRangeErrorText: {
+    id: 'authoring.answerwidget.answer.answerRangeErrorText',
+    defaultMessage: 'Error: Invalid range format. Use brackets or parentheses with values separated by a comma.',
+    description: 'Error text describing wrong format of answer ranges',
+  },
 });
 
 export default messages;
diff --git a/src/editors/containers/ProblemEditor/data/OLXParser.js b/src/editors/containers/ProblemEditor/data/OLXParser.js
index 4a390e68cc..b59f57efde 100644
--- a/src/editors/containers/ProblemEditor/data/OLXParser.js
+++ b/src/editors/containers/ProblemEditor/data/OLXParser.js
@@ -57,6 +57,8 @@ export const responseKeys = [
   'choicetextresponse',
 ];
 
+export const answerRangeFormatRegex = /^[([]\s*\d+(\.\d+)?\s*,\s*\d+(\.\d+)?\s*[)\]]$/m;
+
 export const stripNonTextTags = ({ input, tag }) => {
   const stripedTags = {};
   Object.entries(input).forEach(([key, value]) => {
@@ -432,7 +434,7 @@ export class OLXParser {
         [type]: defaultValue,
       };
     }
-    const isAnswerRange = /[([]\s*\d*,\s*\d*\s*[)\]]/gm.test(numericalresponse['@_answer']);
+    const isAnswerRange = answerRangeFormatRegex.test(numericalresponse['@_answer']);
     answers.push({
       id: indexToLetterMap[answers.length],
       title: numericalresponse['@_answer'],
diff --git a/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.js b/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.js
index 5f2d8ca9f7..279294750a 100644
--- a/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.js
+++ b/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.js
@@ -413,16 +413,18 @@ class ReactStateOLXParser {
             const lowerBoundFloat = Number(numerator) / Number(denominator);
             lowerBoundInt = lowerBoundFloat;
           } else {
-            // these regex replaces remove everything that is not a decimal or positive/negative numer
+            // these regex replaces remove everything that is not a decimal or positive/negative number
             lowerBoundInt = Number(rawLowerBound.replace(/[^0-9-.]/gm, ''));
           }
-          if (rawUpperBound.includes('/')) {
+          if (!rawUpperBound) {
+            upperBoundInt = lowerBoundInt;
+          } else if (rawUpperBound.includes('/')) {
             upperBoundFraction = rawUpperBound.replace(/[^0-9-/]/gm, '');
             const [numerator, denominator] = upperBoundFraction.split('/');
             const upperBoundFloat = Number(numerator) / Number(denominator);
             upperBoundInt = upperBoundFloat;
           } else {
-            // these regex replaces remove everything that is not a decimal or positive/negative numer
+            // these regex replaces remove everything that is not a decimal or positive/negative number
             upperBoundInt = Number(rawUpperBound.replace(/[^0-9-.]/gm, ''));
           }
           if (lowerBoundInt > upperBoundInt) {
diff --git a/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.test.js b/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.test.js
index 416fafdcd8..7b852ca64b 100644
--- a/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.test.js
+++ b/src/editors/containers/ProblemEditor/data/ReactStateOLXParser.test.js
@@ -18,6 +18,10 @@ import {
   numericInputWithAnswerRange,
   textInputWithFeedbackAndHintsWithMultipleAnswers,
   numberParseTest,
+  numericInputWithFractionBounds,
+  numericInputWithEmptyUpperBound,
+  numericInputWithSwappedBounds,
+  numericInputWithMissingUpperBound,
 } from './mockData/editorTestData';
 import ReactStateOLXParser from './ReactStateOLXParser';
 
@@ -147,4 +151,41 @@ describe('Check React State OLXParser problem', () => {
       );
     });
   });
+  describe('ReactStateOLXParser numerical response range parsing', () => {
+    test('handles empty upper bound as same as lower', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithEmptyUpperBound,
+        editorObject: numericInputWithEmptyUpperBound,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[0,1.5]');
+    });
+
+    test('handles swapped bounds and corrects order', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithSwappedBounds,
+        editorObject: numericInputWithSwappedBounds,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[2,5]');
+    });
+
+    test('fixes swapped fraction bounds and preserves brackets', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithFractionBounds,
+        editorObject: numericInputWithFractionBounds,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('(1/2,3/2)');
+    });
+
+    test('sets upper bound = lower bound if upper bound missing', () => {
+      const parser = new ReactStateOLXParser({
+        problem: numericInputWithMissingUpperBound,
+        editorObject: numericInputWithMissingUpperBound,
+      });
+      const result = parser.buildNumericalResponse();
+      expect(result[':@']['@_answer']).toBe('[,2.5]');
+    });
+  });
 });
diff --git a/src/editors/containers/ProblemEditor/data/mockData/editorTestData.js b/src/editors/containers/ProblemEditor/data/mockData/editorTestData.js
index a96230c46e..a33d947e41 100644
--- a/src/editors/containers/ProblemEditor/data/mockData/editorTestData.js
+++ b/src/editors/containers/ProblemEditor/data/mockData/editorTestData.js
@@ -130,3 +130,51 @@ export const numberParseTest = {
   hints: [],
   question: '<p>What is the content of the register x2 after executing the following three lines of instructions?</p>',
 };
+
+export const numericInputWithEmptyUpperBound = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[1.5,]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithSwappedBounds = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[5,2]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithFractionBounds = {
+  answers: [
+    {
+      id: 'a1',
+      title: '(3/2,1/2)',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};
+
+export const numericInputWithMissingUpperBound = {
+  answers: [
+    {
+      id: 'a1',
+      title: '[,2.5]',
+      correct: true,
+    },
+  ],
+  problemType: 'numericalresponse',
+  settings: {},
+};