Trying to upgrade from Splunk 6.3 to 6.4, why am I getting error "The program can't start because libxml2.dll is missing from your computer"?

Hello I was trying to upgrade Splunk from 6.3 to 6.4, but the installation failed. In the system logs there's a log regarding Libxml2.dll. Application popup: splunk.exe - System Error : The program can't start because libxml2.dll is missing from your computer. Try reinstalling the program to fix this problem. Am I the only one who experienced this problem?