Bought FC3 via Avsim/ Paypal back in Dec. 2013. Have the receipt and all, but can´t find the activation code that I can use to get going installing the module in DCS World 2. Anyone got some tips how to retrieve it if (in this case) it seem to be lost? 

Hello figgios,Have you registered at Eagle Dynamics? All your purchases should be linked to your email and password,If not register then look up your order# that will link to your activation code.

http://www.digitalcombatsimulator.com/en/support/