[SOLVED] MODX gets very slow after some actions

I'm running MODX 2.2.10, after trying to do some actions including updating a certain template or opening new snippet page, MODX gets very very slow! (Backend + Front-end).
As slow as static resources and saving requests timeout. Because of failing to load static resources, manager pages don't load.

I had 2.2.4 and upgraded to 2.2.10 yesterday (Upgrading didn't solve it).
RSS and HTML5 cache settings are disabled.
There is nothing related in MODX error log and PHP error_log.
Server is on Amazon EC2 server.

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Update: I had SyntaxChecker 0.5 beta installed. There were some fatal errors about it on PHP log. Uninstalling it solved problem. [ed. note: AHHP last edited this post 12 years, 10 months ago.]