Manually added CSS class definition for .material-icons:

- For reasons unknown, the definition has disappeard recently.
- We should look into this further, but to fix it as quickly as possible, I'm adding it manually for now.

new-client/public/index.css

@@ -96,3 +96,20 @@ body {
 .introjs-tooltip {
   min-width: 280px !important;
 }
+
+.material-icons {
+  word-wrap: normal;
+  -webkit-font-smoothing: antialiased;
+  text-rendering: optimizeLegibility;
+  -moz-osx-font-smoothing: grayscale;
+  direction: ltr;
+  display: inline-block;
+  font-family: Material Icons;
+  font-size: 24px;
+  font-style: normal;
+  font-weight: 400;
+  letter-spacing: normal;
+  line-height: 1;
+  text-transform: none;
+  white-space: nowrap;
+}