I encountered a error with the trust relationship between my parent domain and child domain. I couldn't reset the trust password nor delete the trust.
I found a solution to this problem. I hope this helps.
"1. Run ADSIEdit in the parent domain.
2. While connecting select default naming context
3. Go to the System container.
4. You should see a TrustedDomain object called CN=<ChildDomainName> -> Delete this object.
5. Go to the Users container.
6. You should see a User object called CN=<ChildDomainName$> Delete this object.
7. Force Replicate throughout the parent domain so all DC's in the parent recognize this change.
8. Perform the steps 1-7 in the child domain as well (TrustedDomain & User object will show CN=<ParentDomainName> & CN=<ParentDomainName$>)
9. Once replicated, reboot the PDC in both domains.
10. In the parent domain, open Active Directory Domains and Trusts, create a new trust with the child domain (create on both sides).
In addition, please check the following:
1. Verify that DNS works find in both domains.
2. On the PDC in the parent domain, type the command nltest /dsgetdc:ChildDomain /force
On the PDC in the child domain, type the command nltest /dsgetdc:ParentDomain /force
and check the result."
Please note that it best that you have a backup copy of your domain controller (PDC) for both child and parent domain before proceeding with above steps.