When terminating sub-lines, user gets error, 'FRM-41050: You cannot update this record'. Why?

When my user tries to terminate a contract sub-line, she is getting the error, 'FRM-41050: You cannot update this record'.  Once she clicks on it, the screen behaves as usual and allows her to terminate the sub-line.  That is, it displays the narrow screen asking for the reason, confirmation, etc. 

This is how she terminates the sub-line:

1.  She opens a service contract

2.  goes to the lines

3.  then clicks on the Pricing/Products tab

4.  then clicks on a sub-line,

5.  then she chooses Tools / Terminate Subline

At this point the error window appears. 

We installed an Oracle patch last weekend, and I'm wondering whether this is a side-effect of that patch.  I've not been able to reproduce this issue in other environments,  However, I cannot find any notice in Metalink about this error appearing at inappropriate times in Service Contracts.