Have a savegame with a persistent bug and thought I would share with you guys 
.
The things I do following the savegame have to be "the same" though, as described:
I take my main hero, and attack the city, defeat the villages and now have a second city. (can do tactical or quick battle, doesn't matter)
I Start building a workshop in the captured city (I chose to locate it near the mountains).
I hit End Turn.
Savegame:
https://www.dropbox.com/s/z1mdy00knot2jsv/Test-123.EleSav
Short movie, introducing the steps up until the crash:
https://www.dropbox.com/s/p02zem725n0jbjc/Test-123%20Movie%20Reference.mp4
Sincerely
~ Kongdej
