I guess the WT files on your PC have become corrupt as well as the installer you used to re-install the game. Download the installer using the link provided below, its my personal mirror and I can guarantee that this installer works. Now as for your problem, if this remedy doesn't work then I'm sorry, but you don't have anything to lose anyway so you might as well give it a go.
1) Uninstall Wolfteam via the Control Panel
2) Delete the AeriaGames folder from C:/ drive. The AeriaGames folder will be in the following path location "C:\AeriaGames
3) Delete your old Wolfteam Installer.
4) Disable your Firewall
and Windows Defender
5) Make sure that your DirectX
and Graphics Card Drivers ( nVidia Geforce
), ( AMD ATI Radeon
) are up to date.
6) Use a piece of software called CCleaner
to clean the computers Temporary Internet Files / Cache and also clean the Registry too.
7) Re-download the Wolfteam Installer from HERE
8 ) Re-install Wolfteam and let it download all the patches, don't interrupt this process otherwise you will end up with corrupt .dll files again.
9) Make sure you run the game Launcher as an Admin - Right click on the launcher icon, and select the option "Run as Administrator
** Ideally its best to add the Wolfteam folder in the exceptions / trusted list instead of disabling your Anti-Virus and Firewall.