Error coming on taking backup

Hi Guys need your help when I am taking backup error is coming "There is an error in database structure. The error (1190 in module 19) may have been caused by the computer or a program.

Table : G/L Account

Key Field: No.

Plz help me resolve this issue.

Thanx in Advance

This error occurs since some lower case letters are entered in code fields. Change these fields to be uppercase and then take backup. Follow this URL.