diff --git a/posimai-sc/index.html b/posimai-sc/index.html
index 547e936f..78737ad3 100644
--- a/posimai-sc/index.html
+++ b/posimai-sc/index.html
@@ -592,23 +592,23 @@ header{display:flex;align-items:center;justify-content:space-between;padding:0 1
             <div class="drill-prog-wrap">
               <div class="drill-prog-label">
                 <span x-text="'試験 ' + (examIdx+1) + ' / ' + examTotal"></span>
-                <span x-text="examCurrentEntry.unit.num"></span>
+                <span x-text="examCurrentEntry?.unit?.num || ''"></span>
               </div>
               <div class="drill-prog-bar">
                 <div class="drill-prog-fill" :style="'width:' + (examTotal ? (examIdx/examTotal*100) : 0) + '%'"></div>
               </div>
             </div>
             <div class="drill-unit-lbl">
-              <span x-text="examCurrentEntry.unit.catLabel + ' — ' + examCurrentEntry.unit.title"></span>
+              <span x-text="(examCurrentEntry?.unit?.catLabel || '') + ' — ' + (examCurrentEntry?.unit?.title || '')"></span>
             </div>
             <div class="q-card" :class="exQCardCls()">
-              <div class="q-text" x-html="safeHtml(examCurrentEntry.q.q)"></div>
+              <div class="q-text" x-html="safeHtml(examCurrentEntry?.q?.q || '')"></div>
               <div class="q-choices">
-                <template x-for="(ch, ci) in examCurrentEntry.q.choices" :key="ci">
+                <template x-for="(ch, ci) in (examCurrentEntry?.q?.choices || [])" :key="ci">
                   <button class="q-choice" type="button"
-                    :class="exChoiceCls(ci, examCurrentEntry.q.answer)"
+                    :class="exChoiceCls(ci, examCurrentEntry?.q?.answer ?? -1)"
                     :disabled="exAnswered()"
-                    @click="doExamAnswer(ci, examCurrentEntry.q.answer, examCurrentEntry.q.exp)">
+                    @click="doExamAnswer(ci, examCurrentEntry?.q?.answer ?? -1, examCurrentEntry?.q?.exp || '')">
                     <span class="choice-key" x-text="keys[ci]"></span>
                     <span x-html="safeHtml(ch)"></span>
                   </button>