Add IP address error/failure

[XCore]

I'm trying to add an IP address at >Server Management >Tools & Settings >IP Addresses and get the following error:
"Error: ifmng failed: SIOCSIFADDR: File exists SIOCSIFFLAGS: Cannot assign requested address SIOCSIFNETMASK: Cannot assign requested address SIOCGIFADDR: Cannot assign requested address SIOCSIFBROADCAST: Cannot assign requested address SIOCSIFFLAGS: Cannot assign requested address /sbin/ifconfig 'venet0:17' '72.98.89.91' netmask '255.255.255.255' up exited with non-zero status 255"

Any help is greatly appreciated.

Thank you!