Issue:
When doing Dynamic CRM OnPremise deployment, you might get above error. I am not sure of the actual root cause but there are few fixes that you can apply.
In my recent blog i have showed a fix for CustomControlDefaultConfig related error : https://rawishblog.wordpress.com/2018/05/10/singleton-retrieve-query-should-not-return-more-than-1-record-manged-solution-import-error-onpremise/
Resolution:
For the above error where it talks about duplicate CustomControlDefaultConfig , you can use below method.
Use below query to find out the duplicates:
with lst as ( select CustomControlDefaultConfigId, count(*) cnt from CustomControlDefaultConfig group by CustomControlDefaultConfigId having count(*) > 1 ) select ent.name, lst.CustomControlDefaultConfigId, cfg.CustomControlDefaultConfigIdUnique, cfg.* from lst inner join CustomControlDefaultConfig cfg on cfg.CustomControlDefaultConfigId = lst.CustomControlDefaultConfigId left join entity ent on ent.ObjectTypeCode = cfg.PrimaryEntityTypeCode
Once you have the duplicates , delete those records from this environment, export the solution again & finally try to import to other environment. Hopefully this will resolve the issue.
Cheers!
Passion Dynamics 