diff --git a/backend/src/main/resources/i18n/messages.properties b/backend/src/main/resources/i18n/messages.properties
index 3f23fc105..2cb49fb3d 100644
--- a/backend/src/main/resources/i18n/messages.properties
+++ b/backend/src/main/resources/i18n/messages.properties
@@ -741,3 +741,4 @@ value.algorithm-cbc-256=CBC (256) - http://www.w3.org/2001/04/xmlenc#aes256-cbc
 value.algorithm-cbc-192=CBC (192) - http://www.w3.org/2001/04/xmlenc#aes192-cbc
 value.algorithm-cbc-128=CBC (128) - http://www.w3.org/2001/04/xmlenc#aes128-cbc
 value.algorithm-cbc-tripledes=CBC (TRIPLEDES) - http://www.w3.org/2001/04/xmlenc#tripledes-cbc
+message.algorithms-unique=Each algorithm may only be used once.
\ No newline at end of file
diff --git a/ui/src/app/core/components/ProtectRoute.js b/ui/src/app/core/components/ProtectRoute.js
index 68420b3b9..77133d9e7 100644
--- a/ui/src/app/core/components/ProtectRoute.js
+++ b/ui/src/app/core/components/ProtectRoute.js
@@ -7,7 +7,7 @@ import { useCurrentUser, useIsAdmin } from '../user/UserContext';
 export function ProtectRoute({ children, redirectTo, ...rest }) {
     const user = useCurrentUser();
     const isAdmin = useIsAdmin();
-    if (isUndefined(user.role)) {
+    if (isUndefined(user?.role)) {
         return <></>
     }
     return isAdmin ? children : <Redirect to={redirectTo} />;
diff --git a/ui/src/app/core/components/ProtectRoute.test.js b/ui/src/app/core/components/ProtectRoute.test.js
index 0edd7662e..477707774 100644
--- a/ui/src/app/core/components/ProtectRoute.test.js
+++ b/ui/src/app/core/components/ProtectRoute.test.js
@@ -6,7 +6,8 @@ import { ProtectRoute } from './ProtectRoute';
 const mockIsAdmin = jest.fn();
 
 jest.mock('../user/UserContext', () => ({
-    useIsAdmin: () => mockIsAdmin()
+    useIsAdmin: () => mockIsAdmin(),
+    useCurrentUser: () => ({role: 'ROLE_ADMIN'}),
 }));
 
 const renderWithRouter = (ui, { route = '/' } = {}) => {
diff --git a/ui/src/app/form/component/widgets/SelectWidget.js b/ui/src/app/form/component/widgets/SelectWidget.js
index 2bf62bb2d..57f18b532 100644
--- a/ui/src/app/form/component/widgets/SelectWidget.js
+++ b/ui/src/app/form/component/widgets/SelectWidget.js
@@ -61,6 +61,7 @@ const SelectWidget = ({
     onFocus,
     placeholder,
     rawErrors = [],
+    uiSchema,
 }) => {
     const { enumOptions, enumDisabled } = options;
 
@@ -120,6 +121,9 @@ const SelectWidget = ({
                 onChange={(event) => {
                     const newValue = getValue(event, multiple);
                     onChange(processValue(schema, newValue));
+                    if (uiSchema.checkOnChange) {
+                        setTouched(true);
+                    }
                 }}>
                 {!multiple && schema.default === undefined && (
                     <option value="">{translator(placeholder)}</option>
diff --git a/ui/src/app/metadata/domain/filter/definition/AlgorithmFilterDefinition.js b/ui/src/app/metadata/domain/filter/definition/AlgorithmFilterDefinition.js
index 51e3fa846..5d19288fb 100644
--- a/ui/src/app/metadata/domain/filter/definition/AlgorithmFilterDefinition.js
+++ b/ui/src/app/metadata/domain/filter/definition/AlgorithmFilterDefinition.js
@@ -11,7 +11,10 @@ export const AlgorithmFilterWizard = {
         },
         algorithms: {
             "ui:options": {
-                orderable: false
+                orderable: false,
+            },
+            items: {
+                checkOnChange: true
             }
         }
     }, BaseFilterDefinition.uiSchema),
@@ -21,7 +24,24 @@ export const AlgorithmFilterWizard = {
     // schema: `${BASE_PATH}assets/schema/filter/algorithm.schema.json`,
     steps: [],
     validator: (data = [], current = { resourceId: null }, group) => {
-        return BaseFilterDefinition.validator(data, current, group, 'algorithmFilterTarget', 'algorithmFilterTargetType')
+        const base = BaseFilterDefinition.validator(data, current, group, 'algorithmFilterTarget', 'algorithmFilterTargetType');
+
+        return (formData, errors) => {
+            const errorList = base(formData, errors);
+            const { algorithms } = formData;
+
+            const dupes = algorithms.filter((item, index) => index !== algorithms.indexOf(item));
+            
+            if (dupes.length) {
+                algorithms.forEach((value, index) => {
+                    if (dupes.indexOf(value) > -1) {
+                        errors.algorithms[index].addError('message.algorithms-unique');
+                    }
+                });
+            }
+
+            return errorList;
+        }
     },
     formatter: (changes) => ({
         ...changes,