Stage-CSE Compay-Partner/CA- Import/Export -Getting server error on field mapping page of Template management

Hi Jaideep Vinchurkar,

Environment: Stage
Company- CSE

Login with Partner/CA
Go to Import/ Export link from Benadmin-> Select template management-> Click on import button-Create template-> Go to till Field Mapping tab-> map the fields-> click on save button

Actual: Getting server error after mapping the fields and click on save and continue button.
Note: Without mapping fields data save successfully.

Expected: After mapping the fields and click on save and continue button it should be save successfully.

PFA:
CC:Sachin Hingole,Prasad Pise,Rakesh Roy,Hrishikesh Deshpande,Sanjana Jadhav