Fixes #188

lib/redux/ui/ui_state.dart

@@ -193,6 +193,8 @@ abstract class UIState implements Built<UIState, UIStateBuilder> {
       currentRoute.endsWith('/edit') ||
       currentRoute.endsWith('refund');
 
+  bool get isInPdf => currentRoute.endsWith('/pdf');
+
   bool get isEmailing => currentRoute.endsWith('/email');
 
   bool get isViewing => !isEditing && !isEmailing;

lib/ui/app/menu_drawer.dart

@@ -658,7 +658,10 @@ class SidebarFooter extends StatelessWidget {
             ),
             IconButton(
               icon: Icon(Icons.info_outline),
-              onPressed: () => _showAbout(context),
+              // prevent the modal from being stuck over the pdf
+              onPressed: state.uiState.isInPdf && kIsWeb
+                  ? null
+                  : () => _showAbout(context),
               tooltip: localization.about,
             ),
             /*