Hi,
There is a restrict delete relationship between Contract and Contract (for renewed/originating contracts).
This means if you have renewed an expired contract, that expired contract is now linked to the renewed contract.
If you need to delete the old expired contract, you will need to either delete all the renewed contracts originating from this one, of remove the "originating contract" reference from all renewed contracts linking to the expired contract you are deleting.
You can query the renewed contracts through advanced find by looking for contracts where originating contract equals the contract you are trying to delete. Once you have your results you can choose what to do with them.
Unfortunately CRM does not allow you to change the relationship behaviour for the originating contract, so these are your only options if you wish to delete them.
See here old thread -
[View:https://social.microsoft.com/Forums/en-US/39484dc7-4f80-4c5c-ba5b-6fa29abfe2a3/deleting-expired-contracts?forum=crm]
