Multi-Row Not Functioning: Increment Row Based on Previous Value When Null

Question

I have a dataset where I'd like to increment the value by 1 in the column "Box" based on the previous value when it is not null.  I've tried using a Multi-Row Formula tool with the parameters listed below, but the result is always still a null value.

Update Existing Field:  Box

Num Rows: 1; Set Values to Closest Valid Row (also tried NULL and 0 or Empty)

No Grouping

Expression:  if isnull([Box]) then [Row-1:Box]+1 else [Box] endif

I've also checked that the Box column is a Double type, not sure what else I'm missing!  Thanks in advance for any ideas you might have!

Current Data Set

BoxDateTypePriceShares9252021-12-01RSU Tax Shares518.9816,9929262021-12-10RSU Tax Shares513.2299272021-12-31RSU Tax Shares538.12783[Null]2022-01-03RSU Tax Shares537.95216[Null]2022-01-04RSU Tax Shares523.85163[Null]2022-01-06RSU Tax Shares523.851,236

Outcome Needed:

BoxDateTypePriceShares9252021-12-01RSU Tax Shares518.9816,9929262021-12-10RSU Tax Shares513.2299272021-12-31RSU Tax Shares538.127839282022-01-03RSU Tax Shares537.952169292022-01-04RSU Tax Shares523.851639302022-01-06RSU Tax Shares523.851,236

mbarone · Accepted Answer

Formula looks fine, and it tests fine for me.  Can you screenshot your configuration, maybe throw a select tool before the multitool to make sure it's a numeric type?

linlysergel · Accepted Answer

I clearly need to sleep more!  I just realized that I was only looking at the input side of the tool, not the output.  Everything is working now and thanks for looking at it!