Victor - The index optimization process is a normal administrative function X1 performs periodically. However, that process typically last only a few seconds to perhaps a couple of minutes. If it runs longer than this it is an indication of a potential problem building or managing the index file structure. The cause of the underlying problem might have several sources making it prohibitive to resolve from the forums. Please submit a support case so that we might investigate this matter fully:
http://www.x1.com/support/submit-case.
http://www.x1.com/support/submit-case.