后台，话题管理，编辑已有话题报错：htmlentities(): Passing null to parameter #1 ($string) of type string is deprecated
调试信息提示文件：
at FormBuilder->fetch() in Topic.php line 247
完整路径：
app/backend/content/Topi...
报错信息：
htmlentities(): Passing null to parameter #1 ($string) of type string is deprecated
经检查发现，是模板中对值进行了转换，但默认初始值是null，因此需要转换一下
打开文件：app/common/controller/Frontend.php
第45行下面，添加：
if (is...
报错信息：
SQLSTATE[42000]: Syntax error or access violation: 1055 Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'peth5.aws_answer.id' which is not function...
登录以后，点击个人主页报错：
SQLSTATE[42000]: Syntax error or access violation: 1055 Expression #1 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'peth5.aws_answer.id' which is not...
报错位置：
appcommoncontrollerPlugins.php on line 89
找到文件位置，发现是从cookie中获取token时，没有初始化，导致的报错。
于是改一改：
$cookie_token=cookie('token');
$cookie_token=$cookie_token?$cookie_token:'';
...
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