Blank screen shows when Cost Plan dates are changed such as to cross multiple yearsDescription Blank screen shows up when cost plan dates are changed. Steps to Reproduce Login a pre-London instance2. Open a Cost Plan record from /cost_plan_list.do?3. Update the start period to an earlier date like FY12: Jan with end date in 2017While creating the cost plan breakdowns, the page blanks out and does not display the expected plan. Workaround On update of the Cost Plan, the record form waits to reload until all Business Rules finish their execution. The responsiveness is dependent on the time span of the Cost Plan between start-end dates, on the number of records already present in the breakdown table. Low processing performance has been observed on some customer instances and is not consistently reproducible. Recent changes in the London release provide a better performance on the Cost Plans relationship. If this issue is still consistent and un upgrade is not possible, it is recommended to split the plan in smaller periods, for example instead of creating one plan for 4 years, two for 2 years each. Related Problem: PRB1238146