diff --git a/MEMORY.md b/MEMORY.md
index 61ee68d..fd67b7d 100644
--- a/MEMORY.md
+++ b/MEMORY.md
@@ -31,6 +31,7 @@
 - [x] **Regra de Registro Único:** Portal agora exibe apenas a primeira batida válida por aula, eliminando duplicidade visual de biometria.
 - [x] **Sincronia de Justificativas:** Ajustada a contagem matemática do Portal para contabilizar faltas justificadas apenas após o aceite do Admin.
 - [x] **Fix Dashboard Crash:** Corrigido erro de "tela preta" no Dashboard causado por acesso inseguro a propriedades nulas durante falhas de API.
+- [x] **Blindagem de Conversão ISO:** Resolvida falha crítica de `RangeError: Invalid time value` em todo o Portal. Agora o sistema ignora datas corrompidas ou inválidas em vez de quebrar a interface inteira.
 - [ ] Próximo Passo: Iniciar a migração do módulo Financeiro para 100% SQL seguindo o padrão do Boletim.
 
 
diff --git a/portal/src/components/Notifications.tsx b/portal/src/components/Notifications.tsx
index ee256d8..0609244 100644
--- a/portal/src/components/Notifications.tsx
+++ b/portal/src/components/Notifications.tsx
@@ -45,7 +45,8 @@ export default function Notifications() {
             message: `Identificamos ${atrasadas.length} ${atrasadas.length === 1 ? 'parcela atrasada' : 'parcelas atrasadas'}. Regularize agora para evitar suspensões.`,
             read: false,
             createdAt: new Date().toISOString(),
-            type: 'alert'
+            type: 'alert',
+            studentId: ''
           };
           allNotifs = [overdueNotif, ...allNotifs];
         }
diff --git a/portal/src/pages/Avaliacoes.tsx b/portal/src/pages/Avaliacoes.tsx
index 93b420a..6b5a2cf 100644
--- a/portal/src/pages/Avaliacoes.tsx
+++ b/portal/src/pages/Avaliacoes.tsx
@@ -757,9 +757,9 @@ export default function Avaliacoes() {
                   <h3 style={{ fontSize: '1.05rem', fontWeight: 700, marginBottom: 4, paddingRight: isDone ? 90 : 0 }}>
                     {exam.title}
                   </h3>
-                  {exam.description && (
+                  {(exam as any).description && (
                     <p style={{ fontSize: '0.8rem', color: 'var(--color-text-secondary)', lineHeight: 1.4 }}>
-                      {exam.description}
+                      {(exam as any).description}
                     </p>
                   )}
                 </div>
diff --git a/portal/src/pages/Dashboard.tsx b/portal/src/pages/Dashboard.tsx
index 9a5f38b..6c79984 100644
--- a/portal/src/pages/Dashboard.tsx
+++ b/portal/src/pages/Dashboard.tsx
@@ -83,8 +83,9 @@ export default function Dashboard() {
       if (lesson.status === 'cancelled') return;
       validLessonsCount++;
 
-      const lessonFullISO = new Date(parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00')).toISOString();
-      const lessonStartMs = parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00');
+      const lessonMs = parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00');
+      const lessonFullISO = !isNaN(lessonMs) ? new Date(lessonMs).toISOString() : '';
+      const lessonStartMs = lessonMs;
       const lessonEndMs = parseLessonDateTime(lesson.date, lesson.endTime || '00:00:00', lesson.endTime ? 0 : 60);
 
       const atts = data.attendance.filter(a => {
@@ -422,7 +423,7 @@ export default function Dashboard() {
             {frequencyPercent}%
           </h3>
           <p style={{ fontSize: '0.8125rem', color: 'var(--color-text-secondary)', marginTop: '0.375rem' }}>
-            {presences} presença{presences !== 1 ? 's' : ''} de {totalCourseLessons} aula{totalCourseLessons !== 1 ? 's' : ''} do curso
+            {presencesCount} presença{presencesCount !== 1 ? 's' : ''} de {validLessonsCount} aula{validLessonsCount !== 1 ? 's' : ''} do curso
           </p>
           <div style={{
             marginTop: '0.75rem', height: 6, borderRadius: 3,
diff --git a/portal/src/pages/Frequencia.tsx b/portal/src/pages/Frequencia.tsx
index 9e911dd..b5e8f18 100644
--- a/portal/src/pages/Frequencia.tsx
+++ b/portal/src/pages/Frequencia.tsx
@@ -145,8 +145,9 @@ export default function Frequencia() {
 
   // Merge and Categorize
   const processedItems = deduplicatedLessons.map(lesson => {
-    const lessonFullISO = new Date(parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00')).toISOString();
-    const lessonStartMs = parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00');
+    const lessonMs = parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00');
+    const lessonFullISO = !isNaN(lessonMs) ? new Date(lessonMs).toISOString() : '';
+    const lessonStartMs = lessonMs;
     const lessonEndMs = parseLessonDateTime(lesson.date, lesson.endTime || '00:00:00', lesson.endTime ? 0 : 60);
 
     // No Manager, ele procura o primeiro registro válido
@@ -220,8 +221,9 @@ export default function Frequencia() {
     // Check window (uses new 24h before/after logic)
     if (!isLessonWithinJustificationWindow(l, now)) return false;
     
-    const lessonFullISO = new Date(parseLessonDateTime(l.date, l.startTime || '00:00:00')).toISOString();
-    const lessonStartMs = parseLessonDateTime(l.date, l.startTime || '00:00:00');
+    const lMs = parseLessonDateTime(l.date, l.startTime || '00:00:00');
+    const lessonFullISO = !isNaN(lMs) ? new Date(lMs).toISOString() : '';
+    const lessonStartMs = lMs;
     const lessonEndMs = parseLessonDateTime(l.date, l.endTime || '00:00:00', l.endTime ? 0 : 60);
 
     // Find if THIS SPECIFIC lesson has attendance/justification
@@ -600,7 +602,9 @@ export default function Frequencia() {
                         ) : canJustify ? (
                           <button
                             onClick={() => {
-                              const timestamp = new Date(parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00')).toISOString();
+                              const lMs = parseLessonDateTime(lesson.date, lesson.startTime || '00:00:00');
+                              if (isNaN(lMs)) return;
+                              const timestamp = new Date(lMs).toISOString();
                               openJustifyModal(timestamp);
                             }}
                             style={{
@@ -706,7 +710,9 @@ export default function Frequencia() {
                         return (isNaN(msB) ? 0 : msB) - (isNaN(msA) ? 0 : msA);
                       })
                       .map(l => {
-                        const ts = new Date(parseLessonDateTime(l.date, l.startTime || '00:00:00')).toISOString();
+                        const lMs = parseLessonDateTime(l.date, l.startTime || '00:00:00');
+                        if (isNaN(lMs)) return null;
+                        const ts = new Date(lMs).toISOString();
                         return (
                           <option key={l.id} value={ts}>
                             {formatDateFull(l.date)}{l.startTime ? ` — ${l.startTime.substring(0, 5)}` : ''}{l.endTime ? ` às ${l.endTime.substring(0, 5)}` : ''}
diff --git a/portal/src/pages/Notas.tsx b/portal/src/pages/Notas.tsx
index 50e3787..ce17e65 100644
--- a/portal/src/pages/Notas.tsx
+++ b/portal/src/pages/Notas.tsx
@@ -213,7 +213,7 @@ export default function Notas() {
                           {periodGrades.map((grade) => {
                             const isActivity = grade.evaluationType === 'activity';
                             const maxScore = grade.maxScore ?? 10;
-                            const isDirect = !grade.examId;
+                            const isDirect = !(grade as any).examId;
 
                             return (
                               <div key={grade.id} style={{