I followed several posts here in the community but still cannot figure out the solution that @Bill Sheboy posted a few years back here.
Scenario is similar to the post and I'm trying to handle null values from my 2 dropdown fields. I was successful in getting the formula to work and post a value when options were selected from both dropdown fields.
Problem: I am trying to account for when a field is null (empty) or changed back to empty. The calculated value stays the same and I get an error in the automation.
I created 2 lookup tables.
Logged the value: {{Likelihood.get(issue.customfield_19663.value)}}
and {{Impact.get(issue.customfield_19664.value)}}
The output is then saved in a custom field called Risk Score using the following formula.
{{#=}}{{Likelihood.get(issue.customfield_19663.value)}} * {{Impact.get(issue.customfield_19664.value)}}{{/}}

I attempted to adjust the edit field formula to be:
{{#=}}{{Likelihood.get(issue.customfield_19663.value|0)}} * {{Impact.get(issue.customfield_19664.value|0)}}{{/}}
to account for empty value but that gave an error:

I am not skilled enough to understand where/how to adjust the flow to account for the empty value. Clearly putting this in the wrong place and/or missing something in this flow.