fix(ui): display error in ui while loading seg (#4433)

extensions/cornerstone-dicom-seg/src/getSopClassHandlerModule.ts

@@ -122,12 +122,17 @@ function _load(
   // and also return the same promise to any other callers.
   loadPromises[SOPInstanceUID] = new Promise(async (resolve, reject) => {
     if (!segDisplaySet.segments || Object.keys(segDisplaySet.segments).length === 0) {
-      await _loadSegments({
-        extensionManager,
-        servicesManager,
-        segDisplaySet,
-        headers,
-      });
+      try {
+        await _loadSegments({
+          extensionManager,
+          servicesManager,
+          segDisplaySet,
+          headers,
+        });
+      } catch (e) {
+        segDisplaySet.loading = false;
+        return reject(e);
+      }
     }
 
     const suppressEvents = true;

extensions/cornerstone/src/services/CornerstoneCacheService/CornerstoneCacheService.ts

@@ -242,7 +242,18 @@ class CornerstoneCacheService {
       if (displaySet.load && displaySet.load instanceof Function) {
         const { userAuthenticationService } = this.servicesManager.services;
         const headers = userAuthenticationService.getAuthorizationHeader();
-        await displaySet.load({ headers });
+
+        try {
+          await displaySet.load({ headers });
+        } catch (e) {
+          const { uiNotificationService } = this.servicesManager.services;
+          uiNotificationService.show({
+            title: 'Error loading displaySet',
+            message: e.message,
+            type: 'error',
+          });
+          console.error(e);
+        }
 
         // Parametric maps have a `load` method but it should not be loaded in the
         // same way as SEG and RTSTRUCT but like a normal volume