Task weights functionality problem

We were using erpnext for our project with a lot of tasks with task weights but after raw 45 we are having problem. Although we are 100% sure that the sum of all task weights is equal to 1 but it keep giving us a message "Total of all weights should be 1. Please adjust weights of all project tasks accordingly. "
But when we delet the last raw and put the weight to the previous raw it works just fine. So please any one solve this for us urgently.

Duplicate https://discuss.frappe.io/t/task-weight-functionality-problem/36423