Error in filing itr 4

Dear Experts,

I am trying to file ITR 4 (SUGAM) using the "Prepare Online" tool provided by income tax department on the income tax efiling portal.

While clicking on the "Preview and Submit" button, I am getting the following error :

NOB BP Invalid Characters. Only following characters are allowed - , @ ; / \ ( ) _ : .

Can somebody please help me with this issue. Thanking you in Advance.

Thanks and Regards,

Dhrunil Bhatt