Slitherine

Game worked fine until I added the AO 1943 Add-on. Now when I try to start the game I get this error message:
The procedure entry point __std_free-crt could not be located in the dynamic link library C;\Panzer Corps 2\PanzerCorps2\Binaries\Win64\PanzerCorps2-Win64-Shipping.exe
Please advise