I am running a WordPress multisite network with sub-directory setup. When I check my error.log file, it is full of entries like this one:
Request exceeded the limit of 10 internal redirects due to probable configuration error. Use 'Limit InternalRecursion' to increase the limit if necessary. Use 'LogLevel debug' to get a backtrace.
The problem was, in my case, one specific rewrite rule in the .htaccess file.