This is the error when doing yum update
---Options Error: Error parsing 'gpgcheck': invalid boolean value
Login as root
grep gpgcheck /etc/yum.repos.d/*
That will spit out a list of files, after each file the gpgcheck result...
you should only have either:
Anything else is an invalid boolean value, if there is something other than 0 or 1 you can just fix it by hand with your favourite editor as root and save.