JD

Steps for switching steam accounts on the same computer and avoiding the decryption of headers failed error: 1. Log out of the first Steam account. 2. Go to C:\Program Files (x86)\Steam\SteamApps\common\Arma 2 Operation Arrowhead and delete the ACR, BMF, and PMC folders. 3. Right click the Steam icon and select Run as administrator. Log in to the second Steam account. 4. Double click Arma 2: Operation Arrowhead and select Play. In about two minutes the ACR, BMF, and PMC expansions will be copied over and installed from the cache for the second Steam account. 5. Enjoy playing on the second account. Repeat steps to revert to first account or another account.

I wanted to update this topic on the simplest method I found to use multiple Arma 2 Operation Arrowhead, Combined Operations, or Arma 2 Complete Steam games on a shared computer. Jump to the last paragraph to see my current solution. The first method I tried was using multiple installation folders for Operation Arrowhead, one for each Steam account. But, this is really just a waste of disk space at about 13.2 GB each installation - although if you have plenty of space, or only a couple of accounts it's the quickest option. For my family with four accounts that ended up being over 50 GB. Later I found out that you can delete the DLCsetup folder once installed to save 2.78 GB. Here is some information on installing to custom directories on Steam: http://www.rockpapershotgun.com/2012/09/11/finally-an-in-built-way-to-choose-steam-install-locations/ Next, I realized that the only folders that really cause the encryption errors are the ACR, BAF, and PMC expansion folders. Together these folders are only 2.77 GB. So, if you make a copy of these expansion folders once OA is properly installed and working for each account, you can swap these folders out for the account you want to log into. Alternatively, you can keep the extra sets of expansion folders in the OA folder and rename them to the name of the account they are for, i.e. ACR John, BAF John, PMC John. Then when you want to use them you can change the desired account folder names back to ACR, BAF, and PMC. Batch files could probably be used to change the folder names automatically for each account, though I never did that. Also, if you are only using Operation Arrowhead, or Combined Operations, or want to use low resolution graphics, then you only need the ACR folder for each account, which is only 1.36 GB (actually, maybe if you want low res graphics you can simply not use any expansions at all, and only install OA - now that I think of this, I plan to test this next because maybe you wouldn't need to mess around with any expansion folders at all). An interesting side effect I found out while playing around with these expansion folders is that if you own at least one account with all three expansions, you can actually install these full expansions onto regular Operation Arrowhead and Combined Operation only accounts that don't have them. To do this, install the expansions with the Steam account that owns them first, then switch to the account that doesn't have them, delete the expansion folders and they will be reinstalled for the active account. This lead me to my current solution, which is to simply delete the expansion folders before anyone uses a different account. I'm going to create a simple batch file to click on to do this automatically. The expansions will then be reinstalled for the active Steam account, which does not take too long since they are essentially just copied over from DLCsetup folder. The DLCsetup folder is only an additional 2.78 GB total no matter how many accounts you want to use this method for. On my computer this cached reinstall of ACR, BAF, and PMC adds an additional 2:20 to the load time of ARMA 2 Operation Arrowhead, but only the first time running it after we switch Steam accounts. Overall, a one time charge of about two minutes per account switch and about 3 GB total extra disk space is not too bad and is the best workaround I have found so far. And, there actually is a benefit too in that it turns our one Combined Operations account into a full Arma 2 Complete account.

I was getting an authentication timeout trying to play DayZ Epoch Namalsk until I updated the regular DayZ to 1.8.1-alpha. Since I wasn't trying to play the regular DayZ specifically, I wasted hours trying all sorts of other things first, like fooling around with BattleEye, reinstalling, firewalls, and antivirus.

So you can't install the game to 3 different directories and have it work?

Are the following the steps to doing that? Or would you recommend anything different? Since nothing else has worked, except buying a non-steam copy of CO for switching keys, which results in low resolution graphics for the DLCs, I'm going to try doing this. http://forums.bistudio.com/showthread.php?176631-Arma-2-DLCs-on-Multiple-Arma-2-OA-keys

We are using three different Steam accounts and the games were installed to each. I think the problem is that Steam uses the same Common game file folder and files for all three players instead of separate ones: C:\Program Files (x86)\Steam\SteamApps\common\Arma 2 Operation Arrowhead So how would you specifiy that is should installed to separate folders for each user? My recommendation; DON'T BUY THE STEAM VERSION, especially when the regular version is the same price.

Any idea why this only happens with the Steam version? Or do you think the decryption problem is caused by the newer Complete bundle and not the older Combined bundle?

So, without any solution here in the forums, or from the Bohemia Interactive support email, I did my own research and testing and found that this decryption of headers issue is specifically related to either the Steam version of Arma 2 Complete, or the Arma II Complete bundle itself. How do I know? After finding a workaround elsewhere for Combined Operations non-Steam version, I went ahead and purchased it to test out. Sure enough, the workaround functioned flawlessly with Combined Operations non-Steam, but not with my copies of Arma 2 Complete for Steam. The workaround involves changing the game key by loading a single registration file for each person's copy of the game. Using this workaround as many people can play the game on the same computer as desired. It's very disappointing that nobody here in the BI forums or at BI Studio support appears to know this. You would think BI would be interested in selling more copies of their games and address or correct this issue. If you have Combined Operations, or maybe the non-Steam version of Arma 2 Complete, here is the workaround: 1. For each person's copy of the game create a .reg (registry) text file for their Arma game keys as such: If the game is already installed you can navigate to each directory above in regedit.exe and export the hex key. Make sure to delete everything else in the exported file except for the above lines. 2. You can give the .reg text file any name you like, just use the .reg extension so the registry editor will automatically load it when double clicked. To make it easy, I gave mine the name of each player, i.e. "john.reg" "mary.reg" 3. To switch players simply double click the desired .reg file to change the game keys before loading the game.

This is not a solution. After deleting each expansion folder, and then waiting for each of the expansions to verify, the game will finally load without error. However, the error reoccurs ever time anyone else tries to play their copy of the game: ARMA 2 OA: Failed to load file "C:\Program Files (x86)\common\ARMA 2 Operation Arrowhead\PMC\addons\air_pmc.pbo" - decryption of headers failed.

I deleted the BAF folder and then verified the integrity of BAF which resulted in BAF being copied back to the OA folder. I also verified the integrity of OA which resulted in a message stating that 2 files would be reacquired. However, although slightly different, I still get a very similar error: ARMA 2 OA: Failed to load file "C:\Program Files (x86)\common\ARMA 2 Operation Arrowhead\ACR\addons\air_acr.pbo" - decryption of headers failed. Since I last posted I tried creating a new Windows 8.1 account and running the game from there as an admin, but that had no effect. The same decryption error occurred.

Update: See my workaround in this post here. I recently purchased three copies of ARMA II Complete from the Bohemia Interactive store and installed them to multiple Steam accounts. The first copy I installed works fine for one of my kids, but the other two have one of the following errors when loading Operation Arrowhead, Army of the Czech Republic (ACR), British Armed Forces(BAF), or Private Military Company(PMC): ARMA 2 OA: Failed to load file "C:\Program Files (x86)\common\ARMA 2 Operation Arrowhead\BAF\addons\air_d_baf.pbo"" - decryption of headers failed. ARMA 2 OA: Failed to load file "C:\Program Files (x86)\common\ARMA 2 Operation Arrowhead\ACR\addons\air_acr.pbo" - decryption of headers failed. ARMA 2 OA: Failed to load file "C:\Program Files (x86)\common\ARMA 2 Operation Arrowhead\PMC\addons\air_pmc.pbo" - decryption of headers failed. I have searched Google and the forums for solutions and none of the suggestions seem to work for my situation or there were no replies to posts that matched this issue. I tried installing and running as an admin, I tried editing the registry to give full permissions on the arma 2 oa folder, I ensured the game was fully updated, and I followed numerous specific installation instructions. Since the first copy works fine, it appears to be an installation issue when multiple copies of the game are purchased and installed. Does the installer not use separate folders for account specific information like game keys and profiles? The original ARMA II game works fine on all copies.

I'm having the exact same issue with copies of ARMA II Complete. It's a shame you did not get a single reply on a new purchase of ARMA X Anniversary. That is a very sad reflection upon the BI forums. Did you ever find a solution?

I'm having the same issue with new copies of ARMA II Complete. One actually works fine, but the other two get the exact same air_pmc.pbo decryption error. Thanks for posting a workaround even though nobody ever bothered to reply to you. I don't want to have to remove something I paid for though. I'm beginning to see the BI forums are probably not the best way to get support.

I recently bought 3 copies of ARMA II Complete from the BI store. The first copy works fine, however when either I or my other son tries to run our copies we get decryption errors for PMC. Would this utility solve the problem?

This issue still occurs with newly purchased copies of ARMA II Complete. I bought 3 directly from the Bohemia Interactive store. The first one installed and plays fine. However, when either I or my other son tries to play our copies we get a Decryption of Headers Failed error. Making copies of the individual game folders and copying them over each time might be a cumbersome workaround, but it's not very viable. This is not acceptable on newly purchased games. Is there a fix now?