Scripted field calculation with division

[jogabonito (Lars Christian Østgaard)]

Hi

I want to make a scripted field using a simple calculation by using summation and dividing, but I just keep getting 0 and the error-message:
"Unable to write index pattern! Refresh the page to get the most up to date changes for this index pattern."

I want to calculate the percentage of:
(collected_va + collected_ems10) / (expected_va + expected_ems10)

All documents contains values in all 4 fields.
expected_va and expected_ems10 is always greater than 0
collected_va and collected_ems10 is always greater than 0

I use the following code:

(doc['collected_va'].value + doc['collected_ems10'].value) / (doc['expected_va'].value + doc['expected_ems10'].value)

What do I do wrong here?

[flash1293 (Joe Reuter)]

@jogabonito

Unable to write index pattern

This means your user can't write the index pattern saved object, probably due to permission problems. Make sure your user has "All" permissions for the "Management > Index pattern management" privilege.