Unable to add additional IPv6 addresses to VPS if IPv4 limit in the limit group is set as 0 in SolusVM 2

Symptoms 

Unable to add additional IPv6 addresses to VPS if IPv4 limit in the limit group is set as 0 in SolusVM 2:

SVM_ERROR: Failed to create an additional IP. The limit of 0 additional IPs was exceeded.

Cause

SolusVM 2 bug with ID #SIO-4936 which was fixed in SolusVM Version 2.0.0-28788

Resolution

Update SolusVM 2 to the latest mainline version.