重新安装phpMyAdmin无法运行的解决一例

重新下载phpMyAdmin，并解压覆盖老的版本。

浏览器打开显示 http 500

查看服务器日志显示主要如下：

PHP Fatal error:  PMA\\libraries\\ThemeManager::initializeTheme(): 

The script tried to execute a method or access a property of an incomplete object.
Please ensure that the class definition 

"PMA_Theme_Manager" 

of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide a __autoload() function to load the class definition in /phpMyAdmin/libraries/ThemeManager.php on line 475

搜索一圈有说是要清 cookie：https://github.com/phpmyadmin/phpmyadmin/issues/12123

换个其它从来没打开过的浏览器果然好了，于是清一下 cookie，果然也好了。