Hi, I have recently had this issue in SSRS2012 when trying to export reports to Excel. I found the problem was caused by -0 values in the report. These values appeared where I was trying to calculate a percentage by dividing two field values in the expression of a cell. Changing the format of values on the report did not fix the problem. The problem was made more complex because the cell concerned was being sub-totalled and totalled.
I was able to resolve the problem by doing the following:
1. calculate the percentage values in a calculated column in the dataset
2. use this calculated value in a SWITCH statement in the expression of the cell to filter out any values that equal zero
3. do the rest of the percentage calculation in the cell expression to enable correct sub-totalling
Here is an example of my SWITCH statement:
sum(Fields!percent_change.Value)<> 0, sum(Fields!net_donors.Value) / (sum(Fields!active_donors.Value)-sum(Fields!net_donors.Value)) * 100
Hope this helps.