NetVault Server settings is usually accessed by clicking Change Settings on the left navigation pane. Configuration values for the Schedule Manager, Media Manager, Process Manager, among others can be changed on this screen. When one of the icons on the NetVault Server or a Client settings screen is clicked, a screen with a couple exclamation marks❕tooltips are displayed; no fields are shown. The lines with the different options are unavailable.

There is a problem loading the information from the configuration files. This can happen when when there is something wrong with the contents of the config files.
When modifying configuration files in the …/%NVHOME%/config directory, typically backup of these files are made prior making any changes. These extra copies cause the WebUI corruption; backups should be stored outside of this directory. This can also happen if foreign files are stored on the directory.
The configuration files are stored in the config folder where NetVault Backup is installed. Check for any .cfg files that look like they don't belong (i.e. diskdevices - copy.cfg) and move them to a folder outside of the NetVault installation directory. As a clue, look for files with recent modification dates or that is different to the one of most config files.
There may also be something wrong with the contents of the config files. Check for unusual characters. If one is found, it can be replaced with one from another installation of the same version.