My site is going down once or twice a day when it starts throwing the exception \"Front controller reached 100 router match iterations\". Once this happens access to the adm
Finally I get over the issue, it was due to sortorder in etc frontend di.xml 20 .I changed 20 to 60 and the error disappeared.
20
See: Magento 2.1.2 Rourter action factory gets in to an infinite loop