We have an on premise CRM 4.0 rollup 10 deployment, and our client have requested a number of duplicate detection rules upon leads. We started the development of the rules but when we tried to publish then the system informed us that only 5 rules where allowed per entity.
After some googling we found a solution to our problem. In MSCRM_CONFIG database table DeploymentProperties witch holds the constraint of max 5 rules per entity. With a simple query and a full restart of IIS – CRM Asynchronous Service we were able to publish more than 5 rules.
The query for max 7 duplicate detection rules was:
update DeploymentProperties set
IntColumn = 7
where ColumnName = 'DupMaxPublishedRules'
The above solution is not supported by Microsoft and can cause serious performance issues, but in our case (the number of leads is relatively small) we didn’t have any problem.