🚀 go-pugleaf

I'm working with a file that contains two long tables. It also contains several conditional texts. The primary conditional texts are Text B (underlined in blue, if that's relevant) and Text C (double-underlined in red).
I can set the Show/Hide Conditional Text settings to display both (or All) conditional texts, along with the Condition Indicators, then make changes in the file, and save it.
However, when I change the Show/Hide Conditional Text settings to display only Text C, then try to save it, FrameMaker crashes.
I've tried creating new tables in a new file, and copying the contents of the original tables into the new files. When I brought the contents of the first table into the new file, then selected Text C and saved, it worked. When I brought in the contents from the second table and selected Text C and saved, FM crashed.
The file size is 97KB, with no graphics.
My operating system is Windows NT 4.00.1381.
I'm using FM 5.5 (it's for an old project that won't die; we're using FM 6.0 for all our current stuff).
Thanks!
BILL