Strange error from AppleScript accessing FM Server

I have a FileMaker server with a couple databases, and I have a few AppleScript scripts to output some of the info into files. My syntax to read a value from a field is

tell application "FileMaker Pro Advanced"

set type to get data cell "Example Field" of record 1 of window "Example-DB"

end tell

The window is fine, and I have other lines of script that look like this that work fine. However this line throws an error:

error "FileMaker Pro Advanced got an error: Your access privileges do not allow this action." number -10004

The documentation states that

This error is a actually a generic Apple event error message that is triggered anytime you try to enter data into a field that cannot be edited.

(from http://help.filemake...le-event-errors)

This doesn't make much sense, as all I'm trying to do is read the field, not edit it, and I was able to do both manually within FileMaker, right after that error occurred. If anyone here has any ideas regarding this odd error, your help would be greatly appreciated. Thanks in advance.