I just realized there is a bug in ATLAS. I found when there is no measurement value supplied (leave the “with value as the number” box empty), you can still click the generate button. However, the backend will return the “Nullpointer” error. It turns out when there is no measurement value (the box leave blank), the SQL generation process will fail (500 error on server-side, /webapi/sql). I know, users should always supply the measurement value if they provide this criterion. so I don’t know whether we should say this is a bug.
See example below.
Maybe make this box mandatory? if the “with value as the number” attribute added.