diff --git a/extensions/cornerstone/src/Viewport/OHIFCornerstoneViewport.tsx b/extensions/cornerstone/src/Viewport/OHIFCornerstoneViewport.tsx
index dfdbf4d70..7c5120452 100644
--- a/extensions/cornerstone/src/Viewport/OHIFCornerstoneViewport.tsx
+++ b/extensions/cornerstone/src/Viewport/OHIFCornerstoneViewport.tsx
@@ -419,7 +419,7 @@ OHIFCornerstoneViewport.propTypes = {
   displaySets: PropTypes.array.isRequired,
   dataSource: PropTypes.object.isRequired,
   viewportOptions: PropTypes.object,
-  displaySetOptions: PropTypes.arrayOf(PropTypes.object),
+  displaySetOptions: PropTypes.arrayOf(PropTypes.any),
   servicesManager: PropTypes.object.isRequired,
   onElementEnabled: PropTypes.func,
   // Note: you SHOULD NOT use the initialImageIdOrIndex for manipulation
diff --git a/modes/longitudinal/src/index.js b/modes/longitudinal/src/index.js
index e902ba1ff..f3072cf2e 100644
--- a/modes/longitudinal/src/index.js
+++ b/modes/longitudinal/src/index.js
@@ -3,6 +3,10 @@ import toolbarButtons from './toolbarButtons.js';
 import { id } from './id.js';
 import initToolGroups from './initToolGroups.js';
 
+// Allow this mode by excluding non-imaging modalities such as SR, SEG
+// Also, SM is not a simple imaging modalities, so exclude it.
+const NON_IMAGE_MODALITIES = ['SM', 'ECG', 'SR', 'SEG'];
+
 const ohif = {
   layout: '@ohif/extension-default.layoutTemplateModule.viewerLayout',
   sopClassHandler: '@ohif/extension-default.sopClassHandlerModule.stack',
@@ -44,7 +48,7 @@ const extensionDependencies = {
   '@ohif/extension-dicom-video': '^3.0.1',
 };
 
-function modeFactory({ modeConfiguration }) {
+function modeFactory() {
   return {
     // TODO: We're using this as a route segment
     // We should not be.
@@ -119,11 +123,14 @@ function modeFactory({ modeConfiguration }) {
       study: [],
       series: [],
     },
-    isValidMode: ({ modalities }) => {
+
+    isValidMode: function({ modalities }) {
       const modalities_list = modalities.split('\\');
 
-      // Slide Microscopy modality not supported by basic mode yet
-      return !modalities_list.includes('SM');
+      // Exclude non-image modalities
+      return !!modalities_list.filter(
+        modality => NON_IMAGE_MODALITIES.indexOf(modality) === -1
+      ).length;
     },
     routes: [
       {
@@ -131,7 +138,7 @@ function modeFactory({ modeConfiguration }) {
         /*init: ({ servicesManager, extensionManager }) => {
           //defaultViewerRouteInit
         },*/
-        layoutTemplate: ({ location, servicesManager }) => {
+        layoutTemplate: () => {
           return {
             id: ohif.layout,
             props: {
diff --git a/platform/ui/src/Types.ts b/platform/ui/src/Types.ts
new file mode 100644
index 000000000..d6c8581e9
--- /dev/null
+++ b/platform/ui/src/Types.ts
@@ -0,0 +1,20 @@
+import PropTypes from 'prop-types';
+
+/**
+ * StringNumber often comes back from DICOMweb for integer valued items.
+ */
+const StringNumber = PropTypes.oneOfType([PropTypes.string, PropTypes.number]);
+
+/**
+ * StringArray often comes back from dcmjs for single valued strings that
+ * might have multiple values such as window level descriptions.
+ */
+const StringArray = PropTypes.oneOfType([PropTypes.string, PropTypes.array]);
+
+const ThumbnailType = PropTypes.oneOf([
+  'thumbnail',
+  'thumbnailTracked',
+  'thumbnailNoImage',
+]);
+
+export { StringNumber, StringArray, ThumbnailType };
diff --git a/platform/ui/src/components/StudyBrowser/StudyBrowser.tsx b/platform/ui/src/components/StudyBrowser/StudyBrowser.tsx
index d75313b76..5b1b31b0d 100644
--- a/platform/ui/src/components/StudyBrowser/StudyBrowser.tsx
+++ b/platform/ui/src/components/StudyBrowser/StudyBrowser.tsx
@@ -4,6 +4,7 @@ import classnames from 'classnames';
 import { useTranslation } from 'react-i18next';
 
 import { ButtonGroup, Button, StudyItem, ThumbnailList } from '../';
+import { StringNumber } from '../../Types';
 
 const buttonClasses = 'text-white text-base border-none bg-black p-2 min-w-18';
 const activeButtonClasses = 'bg-primary-main';
@@ -140,7 +141,7 @@ StudyBrowser.propTypes = {
               imageSrc: PropTypes.string,
               imageAltText: PropTypes.string,
               seriesDate: PropTypes.string,
-              seriesNumber: PropTypes.string,
+              seriesNumber: StringNumber,
               numInstances: PropTypes.number,
               description: PropTypes.string,
               componentType: PropTypes.oneOf([
diff --git a/platform/ui/src/components/Thumbnail/Thumbnail.tsx b/platform/ui/src/components/Thumbnail/Thumbnail.tsx
index db0743cf2..176ea36a4 100644
--- a/platform/ui/src/components/Thumbnail/Thumbnail.tsx
+++ b/platform/ui/src/components/Thumbnail/Thumbnail.tsx
@@ -3,6 +3,7 @@ import PropTypes from 'prop-types';
 import classnames from 'classnames';
 import { useDrag } from 'react-dnd';
 import { Icon } from '../';
+import { StringNumber } from '../../Types';
 
 /**
  *
@@ -98,7 +99,7 @@ Thumbnail.propTypes = {
   }),
   imageAltText: PropTypes.string,
   description: PropTypes.string.isRequired,
-  seriesNumber: PropTypes.string.isRequired,
+  seriesNumber: StringNumber.isRequired,
   numInstances: PropTypes.number.isRequired,
   isActive: PropTypes.bool.isRequired,
   onClick: PropTypes.func.isRequired,
diff --git a/platform/ui/src/components/ThumbnailList/ThumbnailList.tsx b/platform/ui/src/components/ThumbnailList/ThumbnailList.tsx
index 75cb70013..46ff0ab94 100644
--- a/platform/ui/src/components/ThumbnailList/ThumbnailList.tsx
+++ b/platform/ui/src/components/ThumbnailList/ThumbnailList.tsx
@@ -2,6 +2,7 @@ import React from 'react';
 import PropTypes from 'prop-types';
 
 import { Thumbnail, ThumbnailNoImage, ThumbnailTracked } from '../';
+import * as Types from '../../Types';
 
 const ThumbnailList = ({
   thumbnails,
@@ -110,18 +111,11 @@ ThumbnailList.propTypes = {
       imageSrc: PropTypes.string,
       imageAltText: PropTypes.string,
       seriesDate: PropTypes.string,
-      seriesNumber: PropTypes.string,
+      seriesNumber: Types.StringNumber,
       numInstances: PropTypes.number,
       description: PropTypes.string,
-      componentType: PropTypes.oneOf([
-        'thumbnail',
-        'thumbnailTracked',
-        'thumbnailNoImage',
-      ]).isRequired,
-      viewportIdentificator: PropTypes.oneOfType([
-        PropTypes.string,
-        PropTypes.array,
-      ]),
+      componentType: Types.ThumbnailType.isRequired,
+      viewportIdentificator: Types.StringArray,
       isTracked: PropTypes.bool,
       /**
        * Data the thumbnail should expose to a receiving drop target. Use a matching
diff --git a/platform/ui/src/components/ThumbnailTracked/ThumbnailTracked.tsx b/platform/ui/src/components/ThumbnailTracked/ThumbnailTracked.tsx
index fd9d74014..2e9f5dcf0 100644
--- a/platform/ui/src/components/ThumbnailTracked/ThumbnailTracked.tsx
+++ b/platform/ui/src/components/ThumbnailTracked/ThumbnailTracked.tsx
@@ -3,6 +3,7 @@ import PropTypes from 'prop-types';
 import classnames from 'classnames';
 
 import { Icon, Thumbnail, Tooltip } from '../';
+import { StringNumber } from '../../Types';
 
 const ThumbnailTracked = ({
   displaySetInstanceUID,
@@ -137,7 +138,7 @@ ThumbnailTracked.propTypes = {
   imageSrc: PropTypes.string,
   imageAltText: PropTypes.string,
   description: PropTypes.string.isRequired,
-  seriesNumber: PropTypes.string.isRequired,
+  seriesNumber: StringNumber.isRequired,
   numInstances: PropTypes.number.isRequired,
   onClick: PropTypes.func.isRequired,
   onDoubleClick: PropTypes.func.isRequired,
diff --git a/platform/ui/src/components/ViewportActionBar/ViewportActionBar.tsx b/platform/ui/src/components/ViewportActionBar/ViewportActionBar.tsx
index 8ca11ae58..d7916bbb1 100644
--- a/platform/ui/src/components/ViewportActionBar/ViewportActionBar.tsx
+++ b/platform/ui/src/components/ViewportActionBar/ViewportActionBar.tsx
@@ -4,6 +4,7 @@ import classnames from 'classnames';
 import { Icon, ButtonGroup, Button, Tooltip, CinePlayer } from '../';
 import useOnClickOutside from '../../utils/useOnClickOutside';
 import { useTranslation } from 'react-i18next';
+import { StringNumber } from '../../Types';
 
 const classes = {
   infoHeader: 'text-base text-primary-light',
@@ -336,7 +337,7 @@ ViewportActionBar.propTypes = {
     isTracked: PropTypes.bool.isRequired,
     isRehydratable: PropTypes.bool.isRequired,
     studyDate: PropTypes.string.isRequired,
-    currentSeries: PropTypes.string.isRequired,
+    currentSeries: StringNumber.isRequired,
     seriesDescription: PropTypes.string.isRequired,
     modality: PropTypes.string.isRequired,
     patientInformation: PropTypes.shape({
diff --git a/platform/ui/src/index.js b/platform/ui/src/index.js
index 22661ea13..4d74012df 100644
--- a/platform/ui/src/index.js
+++ b/platform/ui/src/index.js
@@ -3,6 +3,9 @@
 //export { utils };
 
 /** CONTEXT/HOOKS */
+// Export types - need to do as two lines due to a bug in babel
+import * as Types from './Types';
+
 export {
   useCine,
   CineProvider,
@@ -104,3 +107,4 @@ export {
 export { getIcon, ICONS } from './components/Icon/getIcon';
 export { BackgroundColor } from './pages/Colors/BackgroundColor';
 export { ModalComponent } from './contextProviders/ModalComponent';
+export { Types };
diff --git a/platform/viewer/src/components/ViewportGrid.tsx b/platform/viewer/src/components/ViewportGrid.tsx
index 8416daa6c..0bfb7fcb2 100644
--- a/platform/viewer/src/components/ViewportGrid.tsx
+++ b/platform/viewer/src/components/ViewportGrid.tsx
@@ -370,8 +370,9 @@ function _getViewportComponent(displaySets, viewportComponents) {
   const SOPClassHandlerId = displaySets[0].SOPClassHandlerId;
 
   for (let i = 0; i < viewportComponents.length; i++) {
-    if (!viewportComponents[i])
+    if (!viewportComponents[i]) {
       throw new Error('viewport components not defined');
+    }
     if (!viewportComponents[i].displaySetsToDisplay) {
       throw new Error('displaySetsToDisplay is null');
     }