Will buying Origin keys from third-party resellers go though Origin age restrictions

Now, I'm not sure if this actually will work. But the only thing I would recommend to try is to uninstall and install again.

1. Open Origin
2. Right click on the Battlefield 3 cover in Origin
3. The option lowest in the drop menu should be "Uninstall". Click that.
4. When it have uninstalled, try reinstall completely from Origin, no disks.

To download from Origin:

1. Click on the cover of Battlefield 3.
2. A drop menu should appear, giving you the option to "Install".

I hope this will work for you :) And if it does, i wish you luck on the battlefield!

Apparently this particular error is something related to Origin, rather than specifically Battlefield 3. While I haven't found an instance of the error occurring related to the awc.dll library as per your error log, there is a suggestion over on the Origin forums that Battlefield 3 comes with its own repair tool, and that by running the repair tool it is possible to fix this problem specifically for Battlefield 3. The repair tool can be found inside of the Battlefield 3 installation folder within your Origin folder.

The below are other potential fixes for error 262145:5:

There is a forum post over on the Electronic Arts/Origin forums that suggests this is an issue relating to trying to install the game while using Windows 8. The suggestion given by EA support is to run Origin in Windows Compatibility Mode for Windows XP.

If you're not using Windows 8, there are a few other suggestions from EA support such as completely reinstalling Origin. Alternatively this thread suggests a DLL issue which can be resolved by replacing the relevant DLL (in this instance msvcp71.dll) which may also resolve your issue.

Finally, there is this existing question on Arqade for the same error which simply suggests uninstalling your current attempted install for Battlefield 3, and reinstalling it again through Origin.