Cannot edit fields in portal row, *sometimes*

[ce25254]

I'm a software developer, but pretty new to FileMaker, and have been stumbling my way through building a daily assignment scheduling system for students from scratch.  Yesterday when setting up a new layout, I encountered a maddening portal behavior in FileMaker 12 that I cannot figure out at all:  

 

On one of my layouts, I am able to edit fields in a certain portal row.  In another layout, in an apparently identical portal, I cannot edit the fields.  Based on my examination every property of the two layouts, controls, table occurrences, there is no difference that I can detect between the two layouts:  

 

- The field behavior allows data entry in both layouts.  

- I am not in 'find' mode or edit mode

- There are no special security settings in play

- This happens whether I use the same TO or different (copied) TOs

 

The two layouts are based on tables that have only global fields.  On these layouts, the user can select a student (from a value list that gives me a student ID) and a date.  The TO for each layout-specific global table has a relationship from the student and date field to a TO of assignments.  This gives me all assignments for the chosen day.   This TO has a relationship to TO for 'sessions' and 'resources' so that I can populate some user-readable names relevant to the assignment. 

 

On one layout, I can click on the 'resource name' field and edit it, or change a value in a 'status' popup menu.  On the other layout, when I click on the 'resource name' field,  or on the popup menu, the whole portal row is selected, and I cannot put focus on any control.

 

Why can't I edit the fields on the second layout... ?!?

 

I have stripped out almost everything from my .fm12 file and will attach it here in case someone can take a look to help me figure this out.  On the 'Assign a Resouce' layout, the portal rows are editable.  On the 'Daily Student Checklist' layout, you cannot edit anything in the portal rows (I want to edit them!).  If you can help me understand the difference, I would really appreciate it.

 

Thank you in advance,

CE.

 

Portal Debug 2.fmp12.zip

[bruceR]

There are zero records in the table for the second layout. 

 

Make a new record.

[ce25254]

That's it!  Thank you very much.

It never occurred to me, since the global fields seem to hold a value whether or not there are records in the table.