I have the Steam version of Arma2 and Operation Arrowhead bought as Combined Operations. I have installed Ace, the 3 variations of ACEX and CBA, and Arma2 Launcher by Spirited Machine. When I use Arma2 Launcher I get the message 'Addon Extended Event Handlers' requires addon CA_modules_Alice2.' Then when the game has nearly loaded I get the error message 'no entry for bin\config.bin/CfgVehicles/AH6_Base_EPI.scope.' I have tried searching for the answer but no joy. Sometimes there aare links to downloads but sometimes eg to dev-heaven.net they are dead. Any ideas please?

Those errors look like your modloader is just starting Vanilla ArmA2, not OA. Try starting up CO from the steam gameslist, then activating ACE using the expansions submenu.

It could also be being caused by an incorrect installation of cba. If you've got CO, you should only have the @cba modfolder, if you've got the @cba_oa modfolder as well, you should delete it (this is for users that only have OA)

Thanks for that. I tried what you said but could not see any expansions submenu. ACE was loading - I was using Arma2 Launcher. I did only have the @cba modfolder but I tried adding the A2 version of CBA and ended up with one less error message and a different one than before - it is Addon 'Extended_EventHandlers' requires addon CA_PMC. Do you know what that might indicate?

Well, everything is suggesting you've not got OA running. Can you see Takistan in the islands list? (when you start the editor) If not, then that's definitely the issue.

Thanks for that. I found I had to update using Steam - Combined Operations and also do some more research on Six Updater and use the CO option on Spirited Machine's Arma2 Launcher. Then everything worked. I hadn't realized how much Steam would complicate things and will bear this in mind in the future.