diff --git a/src/pages/submissions/SubmissionsPage.tsx b/src/pages/submissions/SubmissionsPage.tsx
index 136182a..58149fd 100644
--- a/src/pages/submissions/SubmissionsPage.tsx
+++ b/src/pages/submissions/SubmissionsPage.tsx
@@ -76,13 +76,25 @@ export const SubmissionsPage: React.FC = () => {
   const participants: ActiveParticipant[] = stats.activeParticipants || []
   const submissionsList: ChallengeSubmission[] = submissions || []
 
+  const normalizedSearchQuery = (searchQuery ?? '').toLowerCase()
+
   const filteredSubmissions = submissionsList.filter((submission) => {
-    const user = submission.user as ChallengeUser
-    const task = submission.task as ChallengeTask
+    const rawUser = submission.user as ChallengeUser | string | undefined
+    const rawTask = submission.task as ChallengeTask | string | undefined
+
+    const nickname =
+      rawUser && typeof rawUser === 'object' && 'nickname' in rawUser
+        ? (rawUser.nickname ?? '')
+        : ''
+
+    const title =
+      rawTask && typeof rawTask === 'object' && 'title' in rawTask
+        ? (rawTask.title ?? '')
+        : ''
 
     const matchesSearch =
-      user.nickname.toLowerCase().includes(searchQuery.toLowerCase()) ||
-      task.title.toLowerCase().includes(searchQuery.toLowerCase())
+      nickname.toLowerCase().includes(normalizedSearchQuery) ||
+      title.toLowerCase().includes(normalizedSearchQuery)
 
     const matchesStatus = statusFilter === 'all' || submission.status === statusFilter
 
@@ -337,13 +349,27 @@ export const SubmissionsPage: React.FC = () => {
             </Table.Header>
             <Table.Body>
               {filteredSubmissions.map((submission) => {
-                const user = submission.user as ChallengeUser
-                const task = submission.task as ChallengeTask
+                const rawUser = submission.user as ChallengeUser | string | undefined
+                const rawTask = submission.task as ChallengeTask | string | undefined
+
+                const nickname =
+                  rawUser && typeof rawUser === 'object' && 'nickname' in rawUser
+                    ? (rawUser.nickname ?? '')
+                    : typeof rawUser === 'string'
+                      ? rawUser
+                      : ''
+
+                const title =
+                  rawTask && typeof rawTask === 'object' && 'title' in rawTask
+                    ? (rawTask.title ?? '')
+                    : typeof rawTask === 'string'
+                      ? rawTask
+                      : ''
 
                 return (
                   <Table.Row key={submission.id}>
-                    <Table.Cell fontWeight="medium">{user.nickname}</Table.Cell>
-                    <Table.Cell>{task.title}</Table.Cell>
+                    <Table.Cell fontWeight="medium">{nickname}</Table.Cell>
+                    <Table.Cell>{title}</Table.Cell>
                     <Table.Cell>
                       <StatusBadge status={submission.status} />
                     </Table.Cell>
@@ -405,8 +431,27 @@ const SubmissionDetailsModal: React.FC<SubmissionDetailsModalProps> = ({
   
   if (!submission) return null
 
-  const user = submission.user as ChallengeUser
-  const task = submission.task as ChallengeTask
+  const rawUser = submission.user as ChallengeUser | string | undefined
+  const rawTask = submission.task as ChallengeTask | string | undefined
+
+  const userNickname =
+    rawUser && typeof rawUser === 'object' && 'nickname' in rawUser
+      ? (rawUser.nickname ?? '')
+      : typeof rawUser === 'string'
+        ? rawUser
+        : ''
+
+  const taskTitle =
+    rawTask && typeof rawTask === 'object' && 'title' in rawTask
+      ? (rawTask.title ?? '')
+      : typeof rawTask === 'string'
+        ? rawTask
+        : ''
+
+  const taskDescription =
+    rawTask && typeof rawTask === 'object' && 'description' in rawTask
+      ? (rawTask.description ?? '')
+      : ''
 
   const formatDate = (dateStr: string) => {
     return new Date(dateStr).toLocaleString('ru-RU', {
@@ -441,7 +486,7 @@ const SubmissionDetailsModal: React.FC<SubmissionDetailsModalProps> = ({
                   <Text fontSize="sm" color="gray.600" mb={1}>
                     {t('challenge.admin.submissions.details.user')}
                   </Text>
-                  <Text fontWeight="bold">{user.nickname}</Text>
+                  <Text fontWeight="bold">{userNickname}</Text>
                 </Box>
                 <Box>
                   <Text fontSize="sm" color="gray.600" mb={1}>
@@ -471,7 +516,7 @@ const SubmissionDetailsModal: React.FC<SubmissionDetailsModalProps> = ({
             {/* Task */}
             <Box>
               <Text fontWeight="bold" mb={2}>
-                {t('challenge.admin.submissions.details.task')} {task.title}
+                {t('challenge.admin.submissions.details.task')} {taskTitle}
               </Text>
               <Box
                 p={4}
@@ -482,7 +527,7 @@ const SubmissionDetailsModal: React.FC<SubmissionDetailsModalProps> = ({
                 maxH="200px"
                 overflowY="auto"
               >
-                <ReactMarkdown>{task.description}</ReactMarkdown>
+                <ReactMarkdown>{taskDescription}</ReactMarkdown>
               </Box>
             </Box>