Great General not working and causing parts of the UI to disappear

[Fancy Salami]

This has happened to me two times, but in different games. Following a successful battle a Great General appears, but as you can see of the screenshot he looks kinda odd. Furthermore when you select him, part of the UI disappear, and among it is the unit options resulting in the general not being useful for anything.

Notice almost all the UI being gone.

If you move the general he floats rather than walk.

Feel free to try to reproduce the error with the attached save.