rt，我在做 P1919 时，提交一次后出现了提交失败和以下信息：

Argument 2 passed to Luogu\Manager\ProblemManager::hasTag() must be an instance of Luogu\Model\Tag\Tag, null given, called in /app/luogu-web/source/src/Library/Judge/Judger/NormalJudger.php on line 122

(代码块不会在一行过长时自动分行，以上是原文，以下是我瞎改的，可能方便看一点)

Argument 2 passed to 
Luogu\Manager\ProblemManager::hasTag() must be
an instance of Luogu\Model\Tag\Tag, null 
given, called in /app/luogu-
web/source/src/Library/Judge/Judger/NormalJudger.php
on line 122