Your need to take a closer look at your scripts. That error message is normally produced when a script step such as Set Field attempts to modify data in a field that is not accessible from the current layout. This could be caused by issues with your relationships or you could be changing layouts at the wrong time in your script as you may be on the wrong layout at the time this script step executes. (This will not be caused by removing a field from a layout.)
Thanks for your response. I have reduced the script to one line: "Goto Layout" or "Goto Related Record". I also set up layouts with one field and one button with a one line script and a portal with one field with a one line script and the error message occurs persists. The error message continues on a blank layout with one "Goto Layout" button. This problem is occurring in all my layouts with different tables.
I am going to suggest that four years of programming in Filemaker gives me enough experience to realize where the problem is and that it is with the script itself.
Neither go to layout nor go to related records will produce this specific error message. I suspect that a script trigger is being tripped by the change in layout/change in record focus and that script is generating the error that you see.
If you have FileMaker Advanced, I recommend enabling the script debugger and then running one of your scripts that changes layouts.
Thanks for the direction. I did find the problem and it was in fact a script trigger that occurred on entry to that layout. Sometimes you can't see the trees for the forest.