Upgrade crm2013 to crm2015 finishes with errors - action Microsoft.crm.tools.admin.publishduplicateruleaction failed

In place upgrade from 2013 to 2015.

Near end of upgrade get the following popup:

I take option to ignore.

At end of upgrade get the following:

The following entries are from the log file (snippet):

14:43:32|   Info| Executing Install action: Microsoft.Crm.Tools.Admin.PublishDuplicateRuleAction
14:43:32|  Error| System.Exception: Action Microsoft.Crm.Tools.Admin.PublishDuplicateRuleAction failed. ---> Microsoft.Crm.CrmException: No criteria have been specified. Add criteria, and then publish the duplicate detection rule.
   at Microsoft.Crm.ObjectModel.DuplicateRuleService.Publish(Guid duplicateRuleId, ExecutionContext context)
   at Microsoft.Crm.Setup.Server.Utility.NewOrgUtility.PublishDuplicateRule(IBusinessEntity duplicateRule, Boolean isUpgrade, ExecutionContext context)
   at Microsoft.Crm.Setup.Server.Utility.NewOrgUtility.OrganizationPublishDuplicateRules(Guid organizationId, Boolean isUpgrade, OrganizationResourceHelper organizationResourcesHelper)
   at Microsoft.Crm.Tools.Admin.PublishDuplicateRuleAction.Do(IDictionary parameters)
   at Microsoft.Crm.Setup.Shared.CrmAction.ExecuteAction(CrmAction action, IDictionary parameters, Boolean undo)
   --- End of inner exception stack trace ---, Error, AbortRetryIgnore, Option1
14:43:58|   Info| InputResult: Retry

The above error occurs 5 times.

I am very new to CRM and although I have searched with Google I cannot see anyone having a similar problem so it looks like it may be a local issue - can anyone help point me in the right direction please?