It seems that you're using an outdated browser. Some things may not work as they should (or don't work at all).
We suggest you upgrade newer and better browser like: Chrome, Firefox, Internet Explorer or Opera

Hi, how to reactivate ffdshow option at the start ?
From gog support
Cycu93 Aujourd’hui à 12:14

Please remove your current installation of ffdshow and install the latest 32-bit and 64-bit version of ffdshow, reboot/restart your computer and check if the problem still persists.

Please also completely remove your current installation of Tex Murphy - Overseer and then install the game again on your computer.
Cycu, Support "