I can assume you are using MCD 4.0 or better with SDS database model.
Been there. Done that.
I made the mistake of renumbering a phone before making it non-resilient.
Took me hours to fix.
I did a lot of hacking around until I was finally able to resolve it and, actually, I don't remember the exact step I took to fix it.
But let's see if I can point you in the right direction.
Take a look at your SDS failures. - I'd bet you have a lot. You're going to end up deleting them and re syncing.
Might as well start with that.
Next, see if you can make the phone - non-resilient. Check your SDS errors again for clues as to what's failing. Clear it.
Next try to make it resilient again, check SDS errors and clear it.
If you can find out in the SDS errors where it's bombing out try to resolve that.
There could be a lot of things to bang on here including DSS buttons and key appearances of or on other phones. You may have to delete them to.
Hopefully that will point you to the right spot so you can resolve it.
Finally, when done, resync your SDS database again.
Ralph