diff --git a/models/judge_state.js b/models/judge_state.js
index 27ae41a..d4369fd 100644
--- a/models/judge_state.js
+++ b/models/judge_state.js
@@ -83,7 +83,7 @@ class JudgeState extends Model {
       submit_time: parseInt((new Date()).getTime() / 1000),
 
       type: 0,
-      type_info: '',
+      type_info: 0,
 
       pending: true,
 
diff --git a/modules/contest.js b/modules/contest.js
index 18e5659..63cce58 100644
--- a/modules/contest.js
+++ b/modules/contest.js
@@ -338,6 +338,7 @@ app.get('/contest/:id/:pid', async (req, res) => {
 
     let problem_id = problems_id[pid - 1];
     let problem = await Problem.fromID(problem_id);
+    await problem.loadRelationships();
 
     contest.ended = await contest.isEnded();
     if (!(await contest.isRunning() || contest.ended)) {
diff --git a/modules/problem.js b/modules/problem.js
index 2340780..a49398b 100644
--- a/modules/problem.js
+++ b/modules/problem.js
@@ -773,7 +773,18 @@ app.get('/problem/:id/download/additional_file', async (req, res) => {
     let problem = await Problem.fromID(id);
 
     if (!problem) throw new ErrorMessage('无此题目。');
-    if (!await problem.isAllowedUseBy(res.locals.user)) throw new ErrorMessage('您没有权限进行此操作。');
+
+    // XXX: Reduce duplication (see the '/problem/:id/submit' handler)
+    let contest_id = parseInt(req.query.contest_id);
+    if (contest_id) {
+      let contest = await Contest.fromID(contest_id);
+      if (!contest) throw new ErrorMessage('无此比赛。');
+      if (!await contest.isRunning()) throw new ErrorMessage('比赛未开始或已结束。');
+      let problems_id = await contest.getProblems();
+      if (!problems_id.includes(id)) throw new ErrorMessage('无此题目。');
+    } else {
+      if (!await problem.isAllowedUseBy(res.locals.user)) throw new ErrorMessage('您没有权限进行此操作。');
+    }
 
     await problem.loadRelationships();