Interesting Janet! Would love to know what you find out. I haven't seen this issue in the past so not sure what might be triggering it.
We HAD set up a validation rule for 2 custom fields (Lead Source and Lead Source Details)... originally I thought that was the issue, as those were presented in the "conflict" fields I had to choose from when I went through the merge field data selection process. However, I looked in SF, and we were given validation approval access," so that didn't seem to be an issue... sure enough...a few tries later, the merge went through just fine. Then, following that, I did another, and got the same error though, this time there weren't conflicts with Lead Source/Lead Source Detail (those fields weren't presented to choose from) but, rather, fields that didn't have validation rules on them (eg, phone number.) ***That said, perhaps it has nothing to do with the fields that are conflicting since technically all fields are merging, whether or not there's a conflict.
Again... would get the error a few times, but then miracuslously, doing the exact same thing again without changing any settings, it would merge just fine.
I'm sure there's a logical reason for it, but would love to resolve it so future merges are as easy as they used to be! 🙂
- Jen