diff --git a/LesionTracker/client/components/viewer/viewer.js b/LesionTracker/client/components/viewer/viewer.js
index 5b0b0a041..ebaf484f5 100644
--- a/LesionTracker/client/components/viewer/viewer.js
+++ b/LesionTracker/client/components/viewer/viewer.js
@@ -1,15 +1,21 @@
+import { Meteor } from 'meteor/meteor';
 import { Template } from 'meteor/templating';
 import { Session } from 'meteor/session';
 import { ReactiveDict } from 'meteor/reactive-dict';
 import { _ } from 'meteor/underscore';
+import { $ } from 'meteor/jquery';
 
 import { OHIF } from 'meteor/ohif:core';
 import 'meteor/ohif:viewerbase';
 import 'meteor/ohif:metadata';
 
-Session.set('ViewerMainReady', false);
-Session.set('TimepointsReady', false);
-Session.set('MeasurementsReady', false);
+Meteor.startup(() => {
+    Session.set('ViewerMainReady', false);
+    Session.set('TimepointsReady', false);
+    Session.set('MeasurementsReady', false);
+
+    OHIF.viewer.stackImagePositionOffsetSynchronizer = new OHIF.viewerbase.StackImagePositionOffsetSynchronizer();
+});
 
 Template.viewer.onCreated(() => {
     const toolManager = OHIF.viewerbase.toolManager;
@@ -24,6 +30,7 @@ Template.viewer.onCreated(() => {
     instance.data.state.set('rightSidebar', Session.get('rightSidebar'));
 
     const contentId = instance.data.contentId;
+    const viewportUtils = OHIF.viewerbase.viewportUtils;
 
     OHIF.viewer.functionList = $.extend(OHIF.viewer.functionList, {
         toggleLesionTrackerTools: OHIF.lesiontracker.toggleLesionTrackerTools,
@@ -36,15 +43,15 @@ Template.viewer.onCreated(() => {
             toolManager.setActiveTool('nonTarget');
         },
         // Viewport functions
-        toggleCineDialog: OHIF.viewerbase.viewportUtils.toggleCineDialog,
-        clearTools: OHIF.viewerbase.viewportUtils.clearTools,
-        resetViewport: OHIF.viewerbase.viewportUtils.resetViewport,
-        invert: OHIF.viewerbase.viewportUtils.invert,
-        flipV: OHIF.viewerbase.viewportUtils.flipV,
-        flipH: OHIF.viewerbase.viewportUtils.flipH,
-        rotateL: OHIF.viewerbase.viewportUtils.rotateL,
-        rotateR: OHIF.viewerbase.viewportUtils.rotateR,
-        linkStackScroll: OHIF.viewerbase.viewportUtils.linkStackScroll
+        toggleCineDialog: viewportUtils.toggleCineDialog,
+        clearTools: viewportUtils.clearTools,
+        resetViewport: viewportUtils.resetViewport,
+        invert: viewportUtils.invert,
+        flipV: viewportUtils.flipV,
+        flipH: viewportUtils.flipH,
+        rotateL: viewportUtils.rotateL,
+        rotateR: viewportUtils.rotateR,
+        linkStackScroll: viewportUtils.linkStackScroll
     });
 
     if (ViewerData[contentId].loadedSeriesData) {
diff --git a/OHIFViewer/client/components/viewer/viewer.js b/OHIFViewer/client/components/viewer/viewer.js
index b2ecef971..e4a23f6a0 100644
--- a/OHIFViewer/client/components/viewer/viewer.js
+++ b/OHIFViewer/client/components/viewer/viewer.js
@@ -1,26 +1,38 @@
+import { Meteor } from 'meteor/meteor';
+import { Session } from 'meteor/session';
+import { Template } from 'meteor/templating';
+import { ReactiveDict } from 'meteor/reactive-dict';
+
 import { OHIF } from 'meteor/ohif:core';
 import 'meteor/ohif:viewerbase';
 import 'meteor/ohif:metadata';
 
-OHIF.viewer = OHIF.viewer || {};
-OHIF.viewer.defaultTool = 'wwwc';
-OHIF.viewer.refLinesEnabled = true;
-OHIF.viewer.cine = {
-    framesPerSecond: 24,
-    loop: true
-};
+Meteor.startup(() => {
+    Session.setDefault('activeViewport', false);
+    Session.setDefault('leftSidebar', false);
+    Session.setDefault('rightSidebar', false);
 
-OHIF.viewer.functionList = {
-    toggleCineDialog: OHIF.viewerbase.viewportUtils.toggleCineDialog,
-    toggleCinePlay: OHIF.viewerbase.viewportUtils.toggleCinePlay,
-    clearTools: OHIF.viewerbase.viewportUtils.clearTools,
-    resetViewport: OHIF.viewerbase.viewportUtils.resetViewport,
-    invert: OHIF.viewerbase.viewportUtils.invert
-};
+    OHIF.viewer = OHIF.viewer || {};
+    OHIF.viewer.defaultTool = 'wwwc';
+    OHIF.viewer.refLinesEnabled = true;
+    OHIF.viewer.cine = {
+        framesPerSecond: 24,
+        loop: true
+    };
+
+    const viewportUtils = OHIF.viewerbase.viewportUtils;
+
+    OHIF.viewer.functionList = {
+        toggleCineDialog: viewportUtils.toggleCineDialog,
+        toggleCinePlay: viewportUtils.toggleCinePlay,
+        clearTools: viewportUtils.clearTools,
+        resetViewport: viewportUtils.resetViewport,
+        invert: viewportUtils.invert
+    };
+
+    OHIF.viewer.stackImagePositionOffsetSynchronizer = new OHIF.viewerbase.StackImagePositionOffsetSynchronizer();
+});
 
-Session.setDefault('activeViewport', false);
-Session.setDefault('leftSidebar', false);
-Session.setDefault('rightSidebar', false);
 
 Template.viewer.onCreated(() => {
     const instance = Template.instance();
diff --git a/Packages/ohif-hanging-protocols/client/protocolEngine.js b/Packages/ohif-hanging-protocols/client/protocolEngine.js
index 96e1b39e5..1a00d23ce 100644
--- a/Packages/ohif-hanging-protocols/client/protocolEngine.js
+++ b/Packages/ohif-hanging-protocols/client/protocolEngine.js
@@ -4,7 +4,6 @@ import { _ } from 'meteor/underscore';
 // OHIF Modules
 import { OHIF } from 'meteor/ohif:core';
 import 'meteor/ohif:viewerbase';
-import 'meteor/ohif:metadata';
 
 // Define a global variable that will be used to refer to the Protocol Engine
 // It must be populated by HP.setEngine when the Viewer is initialized and a ProtocolEngine
diff --git a/Packages/ohif-hanging-protocols/package.js b/Packages/ohif-hanging-protocols/package.js
index 5abd1b1ee..b9ec6ba61 100755
--- a/Packages/ohif-hanging-protocols/package.js
+++ b/Packages/ohif-hanging-protocols/package.js
@@ -19,7 +19,6 @@ Package.onUse(function(api) {
     api.use('validatejs');
 
     // Our custom packages
-    api.use('ohif:metadata');
     api.use('ohif:viewerbase');
 
     api.addAssets('assets/dots.svg', 'client');
diff --git a/Packages/ohif-viewerbase/client/index.js b/Packages/ohif-viewerbase/client/index.js
index 6e53dfe15..96e90e92d 100644
--- a/Packages/ohif-viewerbase/client/index.js
+++ b/Packages/ohif-viewerbase/client/index.js
@@ -5,7 +5,6 @@ import { Viewerbase } from '../namespace';
  */
 
 import './collections';
-import './lib/stackImagePositionOffsetSynchronizer.js';
 import './lib/debugReactivity';
 
 /**
@@ -208,3 +207,7 @@ Viewerbase.TypeSafeCollection = TypeSafeCollection;
 // OHIFError
 import { OHIFError } from './lib/classes/OHIFError';
 Viewerbase.OHIFError = OHIFError;
+
+// StackImagePositionOffsetSynchronizer
+import { StackImagePositionOffsetSynchronizer } from './lib/classes/StackImagePositionOffsetSynchronizer';
+Viewerbase.StackImagePositionOffsetSynchronizer = StackImagePositionOffsetSynchronizer;
diff --git a/Packages/ohif-viewerbase/client/lib/stackImagePositionOffsetSynchronizer.js b/Packages/ohif-viewerbase/client/lib/classes/StackImagePositionOffsetSynchronizer.js
similarity index 96%
rename from Packages/ohif-viewerbase/client/lib/stackImagePositionOffsetSynchronizer.js
rename to Packages/ohif-viewerbase/client/lib/classes/StackImagePositionOffsetSynchronizer.js
index e30d98927..74e86866a 100644
--- a/Packages/ohif-viewerbase/client/lib/stackImagePositionOffsetSynchronizer.js
+++ b/Packages/ohif-viewerbase/client/lib/classes/StackImagePositionOffsetSynchronizer.js
@@ -1,9 +1,9 @@
 import { OHIF } from 'meteor/ohif:core';
 import { Session } from 'meteor/session';
 import { $ } from 'meteor/jquery';
-import { toolManager } from './toolManager';
+import { toolManager } from '../toolManager';
 
-class StackImagePositionOffsetSynchronizer {
+export class StackImagePositionOffsetSynchronizer {
   constructor() {
     this.active = false;
     this.syncedViewports = [];
@@ -208,6 +208,4 @@ class StackImagePositionOffsetSynchronizer {
         OHIF.log.info(`StackImagePositionOffsetSynchronizer getViewportImageNormal: ${errorMessage}`);
       }
   }
-}
-
-OHIF.viewer.stackImagePositionOffsetSynchronizer = new StackImagePositionOffsetSynchronizer();
\ No newline at end of file
+};
\ No newline at end of file
diff --git a/Packages/ohif-viewerbase/client/lib/helpers/isDisplaySetActive.js b/Packages/ohif-viewerbase/client/lib/helpers/isDisplaySetActive.js
index 6b2e9af44..1ea9fe31e 100644
--- a/Packages/ohif-viewerbase/client/lib/helpers/isDisplaySetActive.js
+++ b/Packages/ohif-viewerbase/client/lib/helpers/isDisplaySetActive.js
@@ -1,7 +1,6 @@
 import { Template } from 'meteor/templating';
 import { Session } from 'meteor/session';
 import { $ } from 'meteor/jquery';
-import { viewportUtils } from '../viewportUtils';
 
 import { OHIF } from 'meteor/ohif:core';
 import 'meteor/ohif:viewerbase';
@@ -32,12 +31,6 @@ Template.registerHelper('isDisplaySetActive', (displaySetInstanceUid, viewportIn
         // (Note, viewportData may have more entries!)
         const currentNumberOfViewports = OHIF.viewerbase.layoutManager.getNumberOfViewports();
 
-        // Get active viewport element
-        const activeViewport = viewportUtils.getActiveViewportElement();
-
-        // Get viewports elements
-        const viewportsElement = $('.imageViewerViewport');
-
         // Loop through the viewport data up until the currently displayed
         // number of viewports
         const viewportData = OHIF.viewerbase.layoutManager.viewportData;
@@ -45,7 +38,7 @@ Template.registerHelper('isDisplaySetActive', (displaySetInstanceUid, viewportIn
             const data = viewportData[i];
 
             // If the display set is displayed in this viewport and is active, stop here
-            if (data && data.displaySetInstanceUid === displaySetInstanceUid && viewportsElement.get(data.viewportIndex) === activeViewport) {
+            if (data && data.displaySetInstanceUid === displaySetInstanceUid) {
                 result = true;
                 break;
             }
diff --git a/Packages/ohif-viewerbase/client/lib/viewportUtils.js b/Packages/ohif-viewerbase/client/lib/viewportUtils.js
index 0976d6369..fafbcc565 100644
--- a/Packages/ohif-viewerbase/client/lib/viewportUtils.js
+++ b/Packages/ohif-viewerbase/client/lib/viewportUtils.js
@@ -124,6 +124,10 @@ const clearTools = () => {
 const linkStackScroll = () => {
     const synchronizer = OHIF.viewer.stackImagePositionOffsetSynchronizer;
 
+    if(!synchronizer) {
+        return;
+    }
+
     if(synchronizer.isActive()) {
         synchronizer.deactivate();
     } else {