A portal report displays blank values for data in certain rows/columns.
If these values aren’t expected to be blank then there has been an expression evaluation error at some point. Note that even a single error has the potential to affect multiple rows or columns of data since expression evaluations for data in portal reports is done in batches.
Review the report performance details page and look for any errors, typically those that show (Error) in the Type column. The root cause can be identified from this message.
(Error)
An example of such an error message is:
Eval@reason=Invalid index (0) for list; valid range is empty)
This indicates that a null or zero value is passed as an array index. This can be resolved by introducing a simple null check in the column expression.
This article applies to all versions of Appian.
Last Reviewed: March 2017