The AddonChecker was written for a number of reasons.  One of the main ones was simply to exercise the new .NET pbo and rap libraries!  However, with the release of Operation Arrowhead, BIS created a set of 'common' addons which were actually not common at all.  It's therefore possible for players who do not have both games to run into problems when joining servers.

AddonChecker can tell you if a mission claims to be is 'vanilla' A2 or OA or to require both sets of content (Combined Operations or 'CO').  More importantly it can detect CO missions by analysing the classes used in the mission.sqm and and scripts run by the mission. It can then 'fix up'  those missions to prevent players accidentally joining the mission and then encountering a 'missing addon' error message during the game.

More generally, AddonChecker can give you an idea before release or installation of what addons a mission might need - it's therefore useful for both server admins and mission-makers.


  • Download and run the setup file.
  • You may find that you need to install .Net4 first.
  • The program will appear in your 'Start' menu under "Mac's Tools -> AddonChecker"

How to use

Using the tool is very simple.  After the program starts you can drag any number of pbo files or folders into the main menu.  If you drag a folder, all pbos within that folder will be checked unless the folder-name looks like the name of a mission in which case it is assumed to be an unpacked pbo. 

From the main screen, you can double-click a mission-file to get more detailed information on the addons and classes that it uses.  The three panes show:
  • Addons that the mission explicitly states as requirements in the mission.sqm file
  • Classes that the creator of the mission has placed in the mission with the editor.
  • Potential classes that might be spawned by scripts in the mission
If a mission uses a mixture of A2 and OA content but the mission.sqm only states that it needs 'vanilla' OA or A2, you'll see the 'Force CO' button enabled on this screen.  Pressing this button adds an explicit requirement for utes or takistan to the mission, meaning that only players who own both games will be able to play.  This avoids the problem of players being able to join the mission but then finding that they are missing required content half-way through.

Finally, by double-clicking on a particular addon or class-name, you can get a view of which script files refer to it.  This is useful when trying to work out where a particular reference to a class has come from.

Other tips

  • You can resize all windows and also resize the panes in the addon-details window by dragging on the vertical dividers between them.
  • You can change the sorting order by clicking on the header of a column.
  • Careful - the "Force CO" feature modifies your pbo's directly so make sure you have backups stored before using this.
  • The tool will automatically update itself as new versions become available.


Feel free to use the feedback page.  For more detailed discussions, there is a dedicated thread in the Bohemia Interactive forums.