Maybe this thread could be used to troubleshoot them (not sure that is possible).
The generic error is: Mysqli statement execute error : Duplicate entry for key 'PRIMARY'
Xenforo search results [here]
example (1) : Mysqli statement execute error : Duplicate entry '5' for key 'PRIMARY'
Error vB4 Importer. [thread]
Note: Chris Deeming got this error by disabling addons in quick succession. [thread]
Kier added Chris' fix.
Other example threads with this error.