Unable to start migration in SolusVM: Failed to insert migration into the database

Symptoms 

Unable to start VPS migration in SolusVM:

SVM_ERROR: Failed to insert migration into the database

Cause

Database inconsistency

Resolution

The root cause of the issue was that the database table 'migrations' was lacking column vserveruuid.
To fix this I did the following:

1. Connected to Master node via SSH
2. Backed up the database:
   https://support.solus.io/hc/en-us/articles/360009293960-How-to-create-a-backup-of-SolusVM-database-
3. Accessed the database:
   https://support.solus.io/hc/en-us/articles/360016113531-How-to-connect-to-SolusVM-Master-database
4. Added the column:
   ALTER TABLE migrations ADD vserveruuid varchar(37) DEFAULT NULL;