Hi Vas,
That error means the value you are trying to split is blank.
The dynamic content for "tools" is empty so the split function has nothing to split.
You can use a filter action to filter out blanks or alternatively use a condition to check if the field is blank before splitting it.
You could also start at the trigger and only get items where tools is not blank or at data entry make sure that the field is required so that tools field is never blank (fill it with a default value as well)
