i want to install the new version of Piwik.After uploading its files, in the second stage of downloading, this message is appearer:
This built-in function has been disabled on your host. Piwik will attempt to emulate this function but may encounter further security restrictions. Tracker performance will also be impacted.
Can this problem have a big or harmful effect on this system?

No, it shouldn’t have a harmful effect on the system.