12210 An Internet Server API (ISAPI) filter has finished handling the request
What is going wrong if you see the following logs in ISA server management console and users complain about missing parts in the web page?
12210 An Internet Server API (ISAPI) filter has finished handling the request. Contact your system administrator.
Don’t worry. It’s not your fault, it is your web filtering software tells ISA that something has been blocked so don’t try to fetch anything more from there.
In my case, it is gravatar.com. This website provides some components in WordPress.com, but it is also listed as a malware site and is blocked by the web filter plug-in in ISA server. That also explained why I could never edit Wordpress Widgets in office but everything is fine at home.
It’s not a good news for Gravatar for years; but seems the owner Automattic has never put any effort to clean up the reputation of their domains. The open source world is too liberal to get controlled.