SSRS Web Server HTTP Handler Error

So I've just begun to have random users in the network unable to load reports via the web. After the page essentially times out they receive this error:

The Report Viewer Web Control HTTP Handler has not been registered in the application's web.config file.

Add to the system.web/httpHandlers section of the web.config file,

or add to the system.webServer/handlers section for Internet Information Services 7 or later.

The line that is requested to be added to the web.config file is there. The issue appears to be local to the PC.