My provider updated the memory limit to over 256MB as recommended, but the issue remains. The error page layout changed a little now, but seems to be the same error message.
I attached a screenshot of the error and included the text below.
ERROR: "Includes\ErrorHandler::FATAL_ERROR" (code 2)
Call to a member function map() on a non-object
Any advice on what else it might be? So far I'm only hitting this error when I try to enable Clean URLs from the Environment page.