Probably your Dwarven Axethrowers are causing the crash..
There is a simple fix for this ( it can be done in two ways):
First one!
1. If you have a data folder in your steam/.../ M2TW/ mods folder, which contains models_missile folder, then right mouse click on that same data folder, click on CUT, and PASTE it in your main steam/.../ M2TW folder. Merge FOLDERS when asked, and COPY and REPLACE option for FILES when asked.
2. Then delete map.rwm file in your steam/.../M2TW/ mods/ FOLDER WHERE Third Age TW is installed/ data / world/ maps/ base folder.
Second one!
If you don`t have that data folder in your M2TW/ mods folder, then:
1. Make a NEW FOLDER on your Desktop.
2. Install ONLY TATW 3.2 Patch into this NEW FOLDER.
3. Open this NEW FOLDER, inside there should be two folders present: data and mods folder.
4. Right mouse click on that same data folder, click on CUT, and PASTE it into your main steam/.../ M2TW folder. Merge FOLDERS when asked, and COPY and REPLACE option for FILES when asked.
5. Then delete map.rwm file in your steam/.../M2TW/ mods/ FOLDER WHERE Third Age TW is installed/ data / world/ maps/ base folder.
If that doesn`t work, reinstall TATW using these steps: LINK.
Also, be sure to set your Video Options to lower settings, TATW is a resource demanding game. Here are the things which are good to apply:
In Video Options disable campaign shadows, set Shadow Quality to None, set Shader version to 2, set Texture Quality to Med, disable Bloom and Reflections, Effects Detail to Med or Low..