Warn on restricted data

Change-Id: Ie15049b679d2c7263bd6fb0a30468a04c171dfa3
diff --git a/Changes b/Changes
index a9866f9..f91d5d9 100644
--- a/Changes
+++ b/Changes
@@ -1,6 +1,7 @@
 0.2.10 2023-11-30
     - Change default api port to 443.
     - Update dependency of logback-classic.
+    - Add warning regarding protected data.
 
       This fixes a security issue! Please update!
 
diff --git a/src/main/resources/assets/templates/export.ftl b/src/main/resources/assets/templates/export.ftl
index 07888c8..eeed57d 100644
--- a/src/main/resources/assets/templates/export.ftl
+++ b/src/main/resources/assets/templates/export.ftl
@@ -110,6 +110,8 @@
             </div>
           </fieldset>
 
+          <p>Depending on the settings and add-ons of your browser, it may not be possible to export corpus excerpts that require authentication.</p>
+          
           <fieldset class="form-line">
             <legend>${dict.hitc}</legend>
             <input name="hitc" id="hitc" type="number" min="1" max="10000" value="${defaultHitc}" />