MS Project 2016 Pro, #ERROR on roll up with average RRS feed

  • Question

  • Good morning,

    I've created a simple numeric custom field containing following formula:


    Then, I choose to rollup with "Average" calculation.

    The result is that each task summary displays "#ERROR" i/i the average. Instead, for non summary tasks, the calculation is ok - so problem seem to be in the way MS Project handles roll up averages, because if I choose "Sum" instead of "Average" I get no error but a correct sum.

    Is that a bug ?

    Thanks for your help


    Thursday, November 10, 2016 2:48 PM

All replies

  • Gianluca,

    I cannot reproduce the error.

    - Try another custom number field, and test the rollup-average.

    - Try to enter some values by typing in and test the rollup-average.

    - Exit MS Project and run it again, hit <F9>  and see whether #ERROR disappears.

    Have you applied the latest public update to MS Project ( ? 

    Ismet Kocaman | eBook on Formulas

    Thursday, November 10, 2016 9:00 PM
  • Hi Ismet,

    I updated Project to the latest built, but the problem is still there.

    In a simple numeric field where I type in date there is no problem in average calculation.

    But if the I use the above formula the converted value, that should be numeric, has "something" that prevents Project to calculate the average. If I substitute that formula with another, such as "Val("1")" then it will work.

    Looks like it's a problem with variant to numeric conversion.

    How to raise this to MS ?


    Best Regards


    Sunday, November 13, 2016 8:35 PM
  • Hello Gianluca,

    Pls send me the schedule (or part of it representing the problem) at I will try to solve the issue. 

    PS. You do not need the formula Val(ProjDurConv(Durata;pjDays)). Just use [Duration]/[Minutes Per Day]

    If you have fractional days in the output and the decimal separator is "," (that is, comma) on your system, then the Val function fails.

    Sunday, November 13, 2016 9:30 PM
  • Follow-up post:

    I did not get any files since the issue was resolved by the poster (I don't have the details), so there is no need for further discussion. We can close the topic.   

    Ismet Kocaman | eBook on Formulas

    Wednesday, November 16, 2016 5:25 PM