Actually, the script works very fine there. It spawns defenders for the rebel cities.
What happened is that an Ai faction assassinated the leading generals and thus new generals and their troops were spawned.

Use this guide and move an own FM near that pile and destroy them (be careful, you don't want to conquer the city itself). And make a backup before manipulating anything.
For any other crashes (and especially random crashes) [/url=https://forums.totalwar.org/vb/showthread.php?t=103681]look into the frequent encountered issues[/url].

XSamatan