error occurred while importing data: OpenCursorException.

Summary

Importing data into Account object and few records error with OpenCursorException

Content

I'm doing an data import into account object to update parent account for the child accounts with check box "Enable custom business logic" option. Around 2750 records were imported and out of that 20 records rejected with the below error.

An error occurred during the data import. (MKT-285235) Details: This error occurred while importing data: OpenCursorException.

Below are the list of fields part of data file,

PartyNumber,ParentAccountPartyNumber,Cascade_c
A-1002920087,A-0013847380,Y

Having an Before Update trigger which will execute based on Cascade_c custom field. It will try to fetch few attributes from the parent account and update to the child account and finally set Cascade_c attribute to "N". For the error records, the parent got changed but none of the attributes are modified.