Error while filing ITR2 online

Go to schedule VIA, select the 'section 80U' and delete it. Save the schedule & go for verification of ITR.

done this step, still not able to do verification, shows same error

Fill Rs. 1 in the section and validate.

The solution is that you:
1.    go to Schedules.
2.    Open Schedule VI-A
3.    Expand Part C, CA, and D. Here you’ll find an entry “Deduction under section 80USelf with disability” with value 0.
4.    Select this entry and click the red Delete button.
5.    Click Confirm at the bottom of the page.
When you validate you will still get Category B/D defect error but it will allow you to upload and submit the return.

Yes. This is the solution offered by Help desk also. Taking these steps solved the problem.