We'll need your error log then. See the "How to report issues" pinned topic.
This is on Windows 8.1
Kane's Wrath regular edition
Error: "Could not connect to Kane's Wrath Online"
----- C&C:Online Launcher Start -----
Game: Kane's Wrath
Kane's Wrath Install Path: C:\Program Files (x86)\Steam\steamapps\common\Command and Conquer 3 - Kane's Wrath\
Started game with: ""C:\Program Files (x86)\Steam\steamapps\common\Command and Conquer 3 - Kane's Wrath\CNC3EP1.exe""
Caught CREATE_PROCESS_DEBUG_EVENT from Kane's Wrath. Detaching...
Found game.dat process. PID 14444
*** Starting CA public key patching routine ***
CA public key is expected value.
Successfully patched CA public key.
*** Starting hostname hooking routine ***
Injecting DLL into game.dat process...
Result of injection: Code -1073741582