- Plesk Onyx 17.5 for Linux
- Plesk Onyx 17.5 for Windows
Unnamed checkbox is presented in Tools & Settings > Server Settings for Plesk Onyx 17.5.
Plesk Bug PPPM-8940 which is fixed in Plesk Onyx 17.8.
It is impossible to enable this checkbox, so it is safe to ignore it.
Upgrade to Plesk Onyx 17.8 in case it is required to get rid of it now.
Refer to the following article for additional details: How to upgrade Plesk to the next release