WFTO Heart Of Gold save-game loading bug

Core Information:

Windows 81. Pro, 64-bit, 16GB RAM
Game Build 2.0.5
WFTO Heart Of Gold, Level 1

Bug:
The game plays normally, and save-games can still be loaded from the initial starting screen correctly.
However, while in-game and playing a level, if a save-game is then loaded, either via the menus, or via F9, the bug occurs.
The level is loaded and displayed full-screen, but there is no user-interface overlaid on the screen.
i.e. No map, spells menu, veins of evil, etc.
All the incidental animations are still working, but all the characters are frozen in place.
The level can be scrolled, zoomed, and rotated, but all other user-interface keys are non-functional.
i.e. ESC, F5, and F9 do nothing in this state.
The "hand" is visible and is animated, but it cannot click on, or interact with anything in the game.
No error message is displayed at any point
As the ESC menu key does not work, the only way to exit the game is by killing it with Task Manager.

I have previously played through the main campaign without encountering this loading-bug, and I have now just purchased the Heart Of Gold DLC.
I have tried using the Steam "Verify the integrity of the game files", but they are fine, and that does not affect the bug.
All video and audio divers are up to date.

I have attached the output_log.txt file for your reference.output_log.txt